Thought this could be worth a new topic...
What parts on a CPS2 B-board are interchangeable?
The ROMs have been discussed here:
http://shmups.system11.org/viewtopic.php?f=6&t=29455
What about other parts? For example, the small sub board that contains the SIMMs, would it be possible to swap a broken with a working one? (if the region and board type are the same)