Add an accelerator! 
yeah.. i got one.
but i was just going to tinker about with one of the MB i have....
The thought goes:
Route the 28mhz signal from the oscillator directly to the CLK pin on the cpu. That should in theory run the cpu at 28Mhz.
and add fpu and 4/8MB trapdoor ram card....
This should work, in theory at least. and of course unless one need complicated circuits to maintain the timing with the chipset...
Would be fun to test it out, just to see if it would work....