I just bought one, used, on eBay last month. I'm pleased with it, although the keyboard action is very stiff -- and I speak as an IBM Model M fan.

As a modern version, some kind of enclosure for a Raspberry Pi would seem the obvious answer. Then all it needs is a text-only Linux distro -- easy enough -- and a decent editor with a modern standard UI, such as TextGrinder or Tilde.

ErgoEmacs with a facelift and modernisation might do, but not without it. Ditto Vi. Seen the joke?

"I've been using Vi for a couple of years now. Mostly because I can't work out how to exit."