Seen on eBay, a prototype of the Quadra 800 – a model dating back to 1993 – with a motherboard validated at 40 MHz whereas the commercial version’s 68040 did not exceed 33 MHz. This motherboard, code-named « Wombat », contains a prototype ROM and 8 MB of RAM. The seller has installed the motherboard in a classic Quadra 800 case and is selling the whole unit for $500.
It’s worth noting that information about this motherboard can be found on the essential 68KMLA forum.