Come on, that game can be had for less than $200. I don't see why it needs to be reproed. It is almost getting into the grey area.

At any rate, any Super FX game can be used as a donor, provided it has the same amount of SRAM as Star Fox. I would advise against trying to use Star Fox as a donor, as many Star Fox games use special boards where the chips are globbed on, making it impractical to use as a donor. In fact, I have seen people make reproductions of Star Fox 2 and Super Star Fox Weekend on the same cart, with a toggle switch to change game.