reply to u/actualwoey at https://old.reddit.com/r/typewriters/comments/1gqhied/recommendations_for_reliable_new_small_spool_1_58/

You could see if a local repair shop is parting out a machine or has spools that would work for you. iirc the Corona Zephyr, Skyriter, and the later versions of the Corsair all used that smaller spool size, usually described as 1 5/8" or 1 2/3". https://site.xavier.edu/polt/typewriters/tw-repair.html Once you've got the correct sized spools, you can wind your Amazon ribbon onto them, but you'll likely have to trim it down to fit. (2" spools usually have 16 yards of ribbon while the 1 5/8" accommodate about 12 yards.)

If you can't come up with original metal spools to respool your 1/2" ribbon onto, you can try https://www.ribbonsunlimited.com/category-s/12779.htm which will sell you both in one go.

Some other ribbon options: https://site.xavier.edu/polt/typewriters/tw-faq.html#q1. I've had good luck buying bulk ribbon from both Baco Ribbon and Fine Line.

I've heard some have successfully re-juvenated old ribbon by spraying it (unspooled into a box) with WD-40 or glycerine to re-wet it and then respooling it.

1938 Corona Zephyr Typewriter Service Adjustment Methods by [[Theodore Munk]]