There will be more data and proper atribution here (original author, steam link, original post date, etc) real soon, I promise. This is just like a technical test to see if they're coming in ok at all.
Zombie Exterminator » 1 December 2023 Patch
Explanations added for upgrades.
You can change the weapons parts except first weapons core.
Stocks and bodies can be stacked now. When you put a new stock or body its stats will be stacked. For example if you attach 2 stock with +5 damage weapons damage will be +10.