Yuck!!! Why on earth would anybody want to do that? If you want a machine that's not available, then recreate it using parts as close to the originals in function as possible, sure (as an example, say you couldn't get any 2102 1K*1 RAMs. Use 2114 1K*4 RAMs instead - just a quarter of the number). But to use the logic board out of some other machine attempting to emulate a classic is plain stupid.