Jim...that is interesting....I wonder if our overseas friends can pipe in on that cord....I'm thinking UK power.
Ron -- IBM did offer dual ribbon capability, at least on the A and B Models. Inside the B-Model Executive, as well as a B-Model Standard I had in the past, was enclosed the fabric ribbon. On the machine, you flipped it's lid forward to reveal the spool.
In an earlier post, you may have seen me speak of "earmuffs" That's the two protrusions you see on my Exec under the carriage at the side of the typewriter. Those hold the film/carbon ribbon.
The ribbon switch has an additional detent which turns off/on the fabric ribbon. Actually, it shifts the ribbon advance ratchet from the film ribbon advance to the fabric ribbon advance. When using the fabric ribbon, yes, the frame that presents the ribbon to the oncoming type bar makes quite a jump.
Whereas my C Model has "ribbon rewind" as one of the toggles, these "dualies" ifyou will, had a metal tab inside the typewriter that you pressed to rewind the fabric ribbon.
Something interesting I saw comparing C Models with a user on Vacuumland. My C has two toggles at the left, Ribbon Position, and Ribbon Rewind. His has only the Ribbon Position. I don't know, but wonder, if Ribbon Rewind was done with an internal metal tab, as described above, an additional detent on the Ribbon Position toggle, or some other method.
John