Started to look into what I wrote above and it would seem you are right. The only possibility (for the moment at least) would be to have different data.pbo for different versions, but thats hardly practical.
What you wish to do is possible by just creating a new addon with a new tag and referencing the model form the data.pbo file. This is all speculation on my part of course not being an addon guru. You covering the same ground trampled by thousands of OFP fans, you should really poke around the addons forum theres a plethora of information there.