Big Den's Gameroom has a recommended Restoration Zone to visit as well.
Another decent site is Jame's Homepage. Check out the three restoration projects he's got listed: PacMan, Space Invaders, and Defender.
Russ's Arcade Collecting Page is another site for examples on restoration.
An absolute, must visit
site is RandyFrommcom
-- His Technical
Department has an absolute wealth of valuable information on the inner
workings of arcade machines. Making the cabinet and controls pretty
is all well and good, but if the guts don't work . . .