>1. If you spill coffee into one while it's powered and it stops working
>forever, is there any hope of repair?
You can try opening it up and giving it a good cleaning (all of the
keys and switches, and the PC board), rinse and dry thoroughly, and
check to see if there's a fuse on the PCB which might have blown.
There were quite a few different M models with different PCBs and I
haven't been able to find schematics, so you'd have to inspect the one
you have.
If the large IC (the keyboard-control microprocessor) was damaged, you
might be able to repair the PCB if you can find a parts donor (same
M model) on ePay or elsewhere.
>2. What's the best new replacement?
If you like the buckling-spring design used in the M (as I do), check
with Unicomp. They're still making a couple of models of bucking-spring
keyboard (standard and mini), with both USB and PS/2 interfaces available.
I think they used to offer a repair service for Model M keyboards but
I'm not sure it's still available.
I'm typing this on a vintage-2001 Unicomp.