With MichelAnge, we tried several things unsuccessfully. There are actually 57 plane IDs and the game crashes when adding a 58th entry, and we did not find any tip to fix this.
BUT, it is possible to duplicate slot, with new CLSID, but with same ID. This keeps the same 3D model, same FM, same cockpit BUT you have a new plane.lua file, where you can adjust payloads, flare/chaff number, fuel load, plane name, etc...
This is actually what is done with F-16A/F-16 MLU for exemple. There are four lua files, but only two IDs.
By the way, if you need some help, dear crazyeddie, I think you should explain how you made your conversion. :)
Edit : oops, cross posting ! :D