Only reason i'm asking this is because I only have the broken rgl version.

You can just get any game here, shared by one of the moderators of gta series

https://drive.google.com/file/d/19gHnXCBJ7_1d_Zqk_M_4xXgnZAtIFk0B/view?usp=sharing

I would rather downgrade it

I'm pretty sure the only difference between 1.0, 1.1/Steam, and Rockstar Game Launcher is the EXE