They look to me like they were separated at birth! An initial look at the internals is promising too. Looks like we’ve found our donor boombox to fix up bits and pieces from the other two.

This is the Aiwa CSD-EX80 alongside the boombox section of the Aiwa Mega-CD CSD-GM1. The similarities make it a promising donor candidate, but they do not establish that every PCB or electrical assembly can be swapped between the two machines.