I have an IBM Model D Executive typewriter that looks just like this one: https://www.si.edu/object/ibm-model-d-executive-typewriter:nmah_856656
Well, mine isn't in that pristine of condition, but that's why it was on Facebook Marketplace instead of the Smithsonian.

It takes carbon ribbons. I've seen a few carbon cassettes out there, but does anyone make new carbon spools for this machine?
It needs some work (some of the letters are too sluggish to make an impression, and the ribbon advance frequently gets stuck). But before I try to get it fixed, I don't want a typewriter that requires me to hunt for 40-year-old NOS ribbons on Ebay. Can I still get new ribbons for it?