No problem, I had found a copy of the Wasteland Kings source files for GameMaker Studio online - I cannot remember the link itself but it should be easy to find through google. Regrettably GameMaker Studio is no longer available, only its sequel, so I can't help you with porting GMS to GMSTwo. Feel free to look at the Nuclear Throne discord for modding help (but they almost entirely deal with NTT modding, Wasteland Kings mods are quite antiquated).