Frankly speaking, I see no sense in attempts to use GP3 1.13 instead of GP2-2000 'cause GP3 1.13 doesn't have many options - moreover, in '2024' topic I've already posted basic carskins & carset, and
mikanhassaku made a set for GP3 1.13. You know, I don't use GP3Edit to export/import anymore, only for a pre-performance calculation.
For better result, I prefer to use jam editors, so every livery contains three part of it separately - now we have almost 100 variants of 2024 liveries already ( including the night versions ) so far, so it means about 300 parts overall. Add to this the helmets, and you'll get approximately 400 bitmaps - I just have no time to convert all this for GP3 1.13.
And how are you going to use all the carskins while GP3 1.13 just let you only 11 cars and 22 helmets at all? Overwrite all this for every event?
Maybe it would be much easier not make entities beyond necessary and just use GP3-2000?
As for the helmets, you can extract them from the jams by JamTool2000 and just decrease each to 50% in any simple graphic editor, as MS Paint or IrfanView.
Sorry if I didn't approve your expectations, but I really don't want to waste time while I have a lot to do everyday )