I have had a hard time finding replacement motherboards, and instead bought another SE/30 off ebay.

It needs new caps badly, bad audio and has a strong eerie smell coming from it.

But you may have to purchase another computer.

The replacement computer will be gutted (case is worse than my original, and has burn-in) with the analogue board and PSU will also be shelved. But if anybody wants a case, I can offload that for a MacQuarium project.