Update 10.12.2015 - Added "Dungeon Pieces".Contents:

A.Props:
 - sarcophagus
 - Shrine
 - Book Shelf
 - Fire Dish and stand
 - Candle Dish, stand and candle
The fire is not included.

B.Walls and ceiling
 - simple wall/arch
 - corner wall/arch
 - tri wall/arch
 - tri compensator (two fused arches that fix the length difference between 2 simple arches and a tri)
 - quad wall/arch
 - U arch
 - F arch
 - H arch
 - tri-L arch
 - stairs, upper and lower parts
 - wall with door
 - concave wall (to harbor a statue or a cross)
 - grid
 - column
 - groin ceiling (for big room) - center, side, corner components
 - barrel ceiling (for corridors) - end, intermediate and tri-compensator components

C.Assembled big room + big corridor + 2 branching smaller coridors + props (for testing).
All textures are included.It seems that in the OBJ the materials are messed up.Please use FBX.

With the provided components you can assemble any kind of Diablo dungeon level but keep in mind that I could not predict all the possible configurations and you may lack an appropriate ceiling for the assembly.You may want to weld all the duplicate vertices where the pieces join.
Feel free to replace the provided textures with better ones.Note that I am not happy with the arches, they should benefit from a hand-painted texture (with different UVs); I lack the skills and tools for texture painting ( I can re-unwrap the UVs if required).
There is also an issue with the chamber with the stairs, it cannot use vaulted ceiling becase the vaulted ceiling is too high.No fix for this one yet, except for a flat wood ceiling.
Size reference:
The quad arch ("dun_wall_quad") is
X: 4.334 meters
Y: 4.339 m
Z: 1.2m

Extras: a simplified big chamber with a piece of corridor attached.

Update 19.10.2015 - added"The Church".

Included:
1.Church walls, double door, floor
2.Church tower with stairs and bell
3.Columns and arches
4.Altar with stained glass and wall paintings
5.Stairs to dungeon
6.First chamber of the dungeon
7.Roof with armature
8.Exterior consoles

Size reference:
Tower Shaft
X: 3.359m
Y: 2.848m
Z: 9.346m

Materials:

1.Church_wall - map Steinwand_D1_Diffuse.jpg, each tile is 2x2 meters
2.Ch_roof - map roof_03.jpg (including normal map), each tile is 2x2 meters
3.Rope - map rope.tga, each tile is 0.25x0.25 meters
4.Coloane - map column.jpg, each tile is 1x1 meters
5.Door_Iron - map door_iron.tga (including mask), each tile is 2.5m (width) x 2.8m (height)
6.Dungeon_wall - map Modern-Cream-Blocks_seamless.tga (including normal and specular), each tile is 1.25x1.25 meters
7.podea_biserica - map Pavement_01_UV_H_CM_1.jpg (including normal and specular), 1.2x1.2 meters
8.Door - map door_diff.tga, 1x1 meters
9.Grinzi - map grinda_02.jpg, 1x1 meters
10.Hinge_bars - map Steel_02_UV_H_CM_1.jpg 0.5x0.5 meters
11.altar_cloth - to be replaced
12.Vitraliu, map stained_glass_1_by_shadowresident.tga (with "dirty" variant), tile 1.
13.ch_roof_int - map wood_texture_by_ftisis_stock.tga (with mask), 0.65x0.65 meters
14.wall_paint_01 (with mask), tile 1.
15.wall_paint_02 (with mask), tile 1.
16.Material 146#, map metal_seamless_texture__bronze__by_jojo_ojoj-d7mm9hp.jpg, 2x2 meters each tile
17.Columns (dungeon), map marble_diablo.tga 0.5x0.5 meters (by me)
18.Column_head, map d_column_extr.tga, 1x1 meters

If the supplied tile dimensions are ignored the final result will be bad, some details from the texture will be projected in wrong places of the mesh.
Note that the UV coordinates are not normalized,to avoid texel density mismatch across the meshes,but I should do it in the near future,to be able to render UV templates, paint textures and eliminate the seams from the windows and doors (using "Render to texture").I forced the unwrapping of the UVs to avoid texture painting and to use only tileable textures, and the arches (especially those from the dungeon) are suffering from this.
All screenshots are rendered using only the default ambient lighting, no defined light sources, no shadows or global illumination.
To be able to model the unseen parts of Tristram village I had to find out what inspired its creators and to find some reference images.It seems Tristram was made using as reference a Norse episcopal farmsted (probably Garoar from Greenland) - see the original post Garoar Episcopal Farmstead by MedievalEurope on SktchUp.com
The houses were made of stone with thatced roof.The church/cathedral from Diablo 1 is a modified roman basilica with gothic exterior consoles and a tower.
The in-game isometric screenshot shows no altar at the back of the church, but the in-game "Lazarus" cutscene does, and I used it as a reference for modeling.It was difficult to estimate its size, constrain it to not be visible from the isometric camera; in a real basilica the altar is bigger than the one from my reconstruction.
Please leave some feedback; if the meshes are useless it's pointless to continue making them.

Update 20.09.2015 - added Adria's Shack.This package contains Adria's shack (made plank by plank), her pot suspended with chains and hooks by the frame, and the doors from the previous release "Tristam plaza" with adjusted position and hinges (fully working, with corrected pivot position for rotation and linked to the doors).It was strange to have the doors floating in the frames.I suppose that there is no need to model vials/bottles and a campfire, the ones from Skyrim should work fine.If you require the meshes in another format just PM me and I'll do my best.

Size reference:
Cauldron:
X: 0.975m
Y: 0.975m
Z: 1.17m

Update 15.09.2015: the latest package "Tristram plaza" consists of 8 houses with roof armature, wood floor and stairs
(in Pepin's and Ogden's houses) and a fountain, positioned like in the
town map.All used textures are included.To check the scale - the
dimensions are the same as in the previous release of Pepin's
house/house with round window.Sorry for the cartoon-like look, I hope it
can be fixed by using other textures.

I know there are some Diablo 1 players that wished to be able to play in first person and to enter the houses from Tristram. I'm one of them.
The purpose behind making those meshes is to recreate Tristram (and the dungeons) from Diablo 1 as accurate as possible, and Skyrim's engine seems the best choice
I am sure that the meshes and textures can be improved and you are strongly encouraged to do it. I am a complete noob at modding and I do not own yet Skyrim, so I cannot create a mod myself.
If you include the meshes in your mod I will be glad if you can drop a line in the end of the readme file to credit me for them.
The meshes are provided as OBJ and FBX ( compatible with 2006 version), with smoothing groups.The units used are meters, and the file's scale is 1.0 ( 1 unit = 1 meter). All dimensions are measured from a reference screenshot of Diablo's gameplay, assuming that Griswold is 1.8 meters tall.
The UV's are not normalized to make it simpler for texture tiling. Average texel density is 1024 pixels/meter (with some exceptions). Please use the FBX format, for some unknown reason the texel density (number of tiling for each texture) is messed up in OBJ, probably due to its method for storing the materials.Also the OBJ format cannot store different materials for different face groups of the same mesh.

To check the scale after import in your 3D package I will post some measurements of the uploaded objects:

1.Hell stairs:
A.Floor dimensions:
X: 10m
Y: 10m
Z: 0.2m
B.Fang 01 dimensions:
X: 2.381m
Y: 0.72m
Z: 2.788m

2.Pepin's House:
A.House walls
X: 6.001m
Y: 6.001m
Z: 2.27m

3.Farnham The Drunk's House
A.Stone walls:
X: 5.001m
Y: 3.699m
Z: 3.745m
B.Roof:
X: 5.7m
Y: 4.361m
Z: 3.481m

4.House with round window
A.Stone walls:
X: 3.699m
Y: 5.999m
Z: 3.866m
B.Roof:
X: 5.121m
Y: 6.9m
Z: 3.159m

I removed on purpose the upper part of the roof,it was a pain to chamfer and to unwrap. In most reference images of thatched roof that element was missing.

I did not make the textures (only turned some of them to seamless) - the credits for the textures goes to its creators, who made them available free of charge.
Texture credits:
Dmitriy Chugai www.texturelib.com
http://www.lughertexture.com
http://seamlesstextures.deviantart.com
http://www.10ravens.com/textures/
http://www.spiralgraphics.biz
http://www.mb3d.co.uk/mb3d
http://texturez.com/
Deviant Art - borysses
                  - Obsidian Dawn


More to come.Enjoy!