The final part of the restoration process is fixing the ribbon selection mechanism of the carriage, and reassembly after cleaning. Every single key, every part of the enclosure was thoroughly cleaned with water and dishwashing fluid. It did wonders, the machine looks fresh - good as new!
Also, I had to fix a broken stud on the soundproofing cover to keep it in place. The fix was wasy, though I had to correct it because I didn't notice the screw head getting into way of the sponge holding part. I noticed it after filming this, and replaced the round head screw with a conical head one, with a countersunk hole. Works like a charm now.

Of course, the typewriter's printing function was thoroughly, joyously, and at times, somewhat frustratedly tested on my benchside Thinkpad T61 running Debian. Talk about IBM (well, it was Lenovo, so technically, post-IBM) talking to IBM!