This was spectacular, thank you.

It’s funny, I did do several different searches with several different search-term combinations and the only useful hit I got was the “typewriter repair” subreddit

Happily, the second response sent me to you (and both responses were in line with your recommendations).

One question that’s still outstanding after reading your post: Last year when refurbishing a 117 year-old treadle Singer sewing machine, I found that my solvent of choice quickly revealed itself to be kerosene. It has no smell (especially not compared to even my low-smell mineral spirits) and worked a dream on that Singer.

Any reason not to use kerosene (and one of my many needles-nosed .5oz sewing machine oil bottles) on a 1957 Smith Corona Sterling?

Thank you again for your post and the links out to sites you trust!