I wrote this mod in 2013 to give the game a bit more realism.  Who throws away an assault rifle after firing a few magazines through it instead of cleaning it?
The following is the readme.txt that's included with the mod file:

Repair Kits Revamped Ver 1.05
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Change Log:
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1.05.0-Compatibility added for Stalker 1.0006 (Steam and GOG versions)
1.04.2-New GUI implemented to match game GUI
          -Bug removed that caused icons of salvage items to be invisible
1.04.1-Language Localizations added
1.04.0        -Savlage reimplemented. Major Rewrite
1.03.0-Salvage Weapons Temporarily Removed
1.02.0-Minor Bug Fix
   -ZRP compatibility
1.00.0-Initial Release

Introduction:
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This was a primarily meant as a brain exercise for me as well as a way to learn LUA script.
Eventually I was 500 lines into the code and realized I might as well release this as a mod for the community.
The mod does have it's limitations, but I think it fits in nicely into the game without having a major impact on gameplay.  To me it also adds a bit of realism to the game that wasn't there before.

Purposes of this modification:
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Allow repairing of armor and weapons using a repair kit and spare parts.
The repair kit will appear in your inventory within a few seconds of starting a new game.  You must create spare parts by salvaging weapons and armor.

Item to be repaired or salvaged can be selected from a graphical menu.

Spare Parts to Repair:
Item weight x 3 - item weight x 3 x item condition
Spare Parts from salvage:
Item weight x 3 x item condition

This number can be adjusted via the scrap_mult variable in the repair.script file.

Requirements:
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STALKER Shadow of Chernobyl installed and patched to version 1.0006.  I have not tested this with any
other version of the game and can not verify if it will or will not work with other versions.

This is an English only version.  I may release versions in the future with other languages, but I
feel that anyone can figure out how to use this mod in game without being able to read the titles.
Feel free to make your own localization of the mod, the file structure supports it.

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Installation instructions:
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You do NOT need to start a new game if installing this over a vanilla (unmodded) game.

If you are using a mod other than Stalker Complete 2009 or ZRP 1.07r5, I would suggest using a program like WinMerge to
manually merge the vanilla version of this mod with your existing mod.
WinMerge is avaiable from http://www.winmerge.org and is an invaluable tool for working with Stalker mods.

If you have not installed any mods previously, you should edit fsgame.ltx and change any occurrence of "false" on the second line to "true" (without the quotes) and save your change. The line will look like this when you are finished:

$game_data$           = true|    true|    $fs_root$|        gamedata\

Installation after that point is simple, just copy the gamedata folder that applies to you to your main Stalker folder.  If you plan on customizing ZRP using the modifier program you need to install ZRP first, then this mod, then do any customizing.

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Uninstallation:
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Just delete or rename the gamedata subdirectory.

Note that all saves made with this mod are not compatible with the vanilla game or with an installation that doesn't have this mod installed!

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Credits:
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Thanks go out to the following mods:

[TZP]LoNer1 for the matching GUI.
The ABC team for the ABC Sleeping Bag Mod
The creator of the Repair Kit v1.1 Mod

I used the idea of a repair kit from Repair Kit v1.1 and the idea for repair kit respawn from ABC.