So would this mean one could convert Bully's collison's to GTA SA/VC/III?
Yes, you just need first to convert Bully's collison's to CST using my tool, and than open the CST with colleditor. The coleditor can save it than as SA/VC/III collison's.
I am also worcking on a tool that should be able to read most R* 3D era formats (GTA SA/VC/III, Manhunt 1/2 and Bully) and save GTA SA/VC/III and Manhunt 1/2 formats. I don´t think this tool be finished soon. One of the reasons is, MINGW su**s.