Here are Weapons, Items, and Class Mods I created using the built-in editor from Borderlands (original). I found some time to re-import these items for the Borderlands GOTY Enhanced version. I created weapons or COMs I thought were missing in the vanilla game, or got rid of things I found annoying. The only change from my original Borderlands upload on Nexus, was to change the COMs from having +9 rare item finding (which was useless), to instead increasing magazine capacity. Some highlights:

+ ChiRho & FireFriendly Shotgun -> Modified S&S Crux and Torgue Friendly Fire (no fixed-pattern shots, and always procs)
+ Accucrit Sniper -> Significantly higher critical damage, increased reload speed, Ammo regeneration
+ Omega and DianMu Shotguns -> Always procs at least the lowest level shock elemental damage
+ Nietzsche Rifle -> Always procs shock, heals via transfusion (what doesn't kill you, makes you stronger!)
+ Combustion Jumong Rifle -> Always procs fire, ammo regen
+ Hellfire grenades -> much higher chance of proc-ing than incendiary grenades, and larger AOE radius (don't get too close)
+ COMs -> Made for each character class, increased ROF and magazine capacity. Most have ammo regen and "best-of" skills for each class
+ Rocketman COM for Berzerkers -> 500% increase in fire-rate and magazine size for Rocket Launchers, just for fun
+ Much more including hidden attributes not reflected on the Weapon card.

Pre-Install Requirements:
If you want to import these mod-ed weapons or items into your game, you need the WillowTree editor by XanderChaos and Matt911. Make sure you get a recent version that supports Borderlands GOTY enhanced. The file can be downloaded here:  
https://sourceforge.net/projects/willowtree/ 

Install Instructions:
1. Unzip the "NYTIMZ Custom Items for GOTY Enhanced" folder using winzip or 7zip
2. Put each of the *.upk files in ...\Steam\steamapps\common\BorderlandsGOTYEnhanced\WillowGame\CookedPC\Packages\
3. Open your character's save file (typically in ...\Documents\My Games\Borderlands Game of the Year\Binaries\SaveData\ in the WillowTree editor, go to the Weapons tab (or Items tab if shield, grenade, or COM) and press 'Import' -> 'From File(s)'.
4. Navigate to where you extracted the original NYTIMZ zip folder, and open the 'TXT weapons' or 'TXT items' folder to import weapons or items. In the new WillowTree editor, you can import multiple weapons or items at a time. Select the text file of the same name that accompanied the *.upk files to create it in-game. Optionally 'Save changes' to the weapon level or item quality in the 'Weapon Parts' section to suit your needs. Make sure you save the character in the File -> Save menu, or your changes won't stick.

I've verified everything works using my own Steam account version of Borderlands GOTY Enhanced, so hopefully you do not have any troubles. Good luck and Enjoy!