This has been discussed before, if I remember correctly:
SFC2 Models are usable in SFC1, they are essentially the same model, except the SFC2 models have Light Maps (for the Nacelle glow, deflector, running lights, even windows) that are incompatible with SFC1. Theoretically you can remove the Light Map from the model and it can be used in SFC1.
As for Modifications: They would need a considerable re-write to work between the platforms, it's not impossible, but extremely time-consuming.