The KIM-1 (Keyboard Input Monitor) dates from as early
as 1975 and was Commodore's first 'proper' computer after the calculator business.
It was sold as a kit originally and was more of a 'here's some brief instructions,
figure the rest out yourself' type of build. This machine is a later one (Rev
F) and is marked as Commodore/MOS instead of just MOS, since Commodore bought MOS to get a reliable supply of chips. It also comes with an 8K (count 'em) memory module and EPROM blower made by The Computerist and is all contained in the rather smart and less common case.
*update*. KIM Manuals, memory expansion manuals and a KIM-1
advert found by Lee Davison, the bloke I got this machine from in the first