Hey,
There are a couple of boxes of boards on eBay that look interesting.
Several PDP CPU boards, MOS RAM, etc. No cables or cab kits AFAICT.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2045702233
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2045702595
Wish I could afford 'em.
Doc