Hi, not sure what are you aiming to do ? didn't catch if you want convert the patches for GP3 2k as GP3 113 patches, or getting the original GP3 patches and convert them to GP3-2k?
Anyway. GP3 2K , under wood, is more similar to GP4 than GP3.
The advantage for GP3 2K is you can make patches easly , without carsets editor, cause with the GPxPatch and file of Season (have a look the megapatches based on GP3-2k and or GP3 Universe megapatch), you can manage liveries path files (different liveries per each driver in a team) and performance/driver names, all circuits for all 17 slots to use, by the text files. Have a look to GPxPatch documentation.
Something you cannot do easly will be the debris contacts in GP3. Despite there is also a tool can get long replay in original GP3 , transforming the GP3.exe in GP3v.exe (
control with keys during replay, [ ] ; ' ), but this has some little bug with no perfect magic dataed track, and sometimes with variable weather it doesn't work properly.
I think the only mode to get the debris contacts in original GP3 is to change the exe file in assembly. The author of GPXPatch may know how to do that.