Recently I purchased an Altair 8800 from a friend, S/N 221999 (looks like someone sliced off the 'A' or 'K' from the end of the serial number, but I suspect it's a kit build).
I ended up with the following:
-Chassis
-Display/control board
-Power supply (likely a Rev 0)
-Backplane - 1 ~.062"...