I think this looks like a better daily driver though:
https://www.sanseido-publ.co.jp/publ/im ... n-je-2.gif
This has awesome color too though... time for a group buy?
https://www.jagat.or.jp/past_archives/s ... zawa11.jpg
Ok, but here is your actual keyboard, I think:
https://twitter.com/yukiakari/status/11 ... 80/photo/3
(interesting that the wrist places are discolored/rusty in exactly the same places as yours)
https://d2l930y2yx77uc.cloudfront.net/p ... cbb960.jpg
http://www.arts-net.co.jp/team/wp-conte ... G_5769.jpg
So it's really from a MK-110? Not sure, because seems same as in the photo you posted of the MK-300. Maybe they didn't need to change the keyboard, only the computer that was taking input from it.
I was hoping to find an instruction manual or something that explained how you would use the right-side and left-side buttons to get to the kanji you needed, but no luck so far. You might ask the owner of this site, as he has quite a lot of paper materials, including a user manual for a 1979 predecessor: