Actually there are 4 cost reduced versions of the C64
Original board
Integrated TTL logic into custom PLL Clock chip.
Changed DRAMs to 2x 64k by 4 (replaced 8x 64k by 1)
C64C, integrated more glue logic into the PLA, Changed to HMOS chips from NMOS (Smaller PCB)
C64C, moved the color SRAM chip into the PLA
I think sending Dave more obscure stuff is more interesting, Commodore, Atari & Apple stuff is too common.
How about some 80's Dick smith offerings like ->
Dick Smith VZ 200 / 300, Dick Smith CAT (Apple 2 clone) or Dick Smith Wizzard.