Archimedes C
Bought at a Breker auction, while no-one was paying attention. It was my first stepped drum calculator. I was suprised to have it at the price I paid, but then again, the machine was extremely disgustingly filthy. Someone had oiled the machine by squirting every viewport and input slider full of thick oil, so all you could see of the numbers was a glistening moving oil film. As we all know, better too much oil than too little to protect a machine. It was disassembled completely, cleaned, reassembled, and lightly oiled again. It is a very pleasant machine to work with, as the machine is small, but not so small or light that it will shift easily on a table, and the action is very light. It's serial N° is "2828 A", and it was originally sold in Prague, in that wrapped up house where the pharmacy is now.
It really did say "Archimedes" ... it's just that the machine was used a bit.
Two small finger knobs missing on the carriage ... since repaired.
What has since also changed is the black base of the machine - I have traded the very nice decal of the Prague dealer for a much better Archimedes script.
Finally, a video of the machine in operation.