Hey hap,
is that from that place in the Netherlands? I've been keenly looking for a CS slot riser card for years, but even he doesn't have them. If you ever come across one, please let me know.
Nice score falen5 - I wouldn't go too overboard with the cleaning (and let it dry for a few days in a sunny location, not just one), or worry about caps. Hoping you will get more life out of it. You should also check the sub/PSU cord for any damage, and do a multimeter check to check power is actually getting through
The 6500 board could be modified to fit, once you desolder some connectors and I'm betting the TAM's sound PCB is a straight drop in once soldered. Then all you are missing is the startup chime, but since the 6500 and TAM ROM are exactly the same, I'm betting it's a resistor placement on the board that sets the unique TAM startup chime.