Just a thought for Bill Burkholder and others who have cameras they love that use obsolete film.
I have cut down 4x5 sheet film to use in obsolete plate cameras. This is an almost painfully slow process, but can be used in film cameras that use film with a width greater than 6cm. There are some interesting interwar German cameras that fit this definition. You simply use 4x5 sheet film, and make a cardboard mask to the negative size, then cut it, load it, either directly into the camera or via a single (or dual) frame plate holder for your particular size.
For 2 1/4 by 3 1/4 roll or sheet film cameras, you can cut 2 1/4 (6 cm) sheet film to single plates using the same carcboard template. Just keep cutting the 6 cm film to the 3 1/4" width, and load into film or plate holders.
127 film cameras pose a special challenge, as you need to cut the film in two directions, then respool it onto a 127 spool. It's actually easier than you might expect. I would do this if I had a high end 127 camera like a Baby Rollei. Alas, I don't.... Lomo has your answer here:
https://www.lomography.com/magazine/266162-cut-127-film-by-yourself-a-quick-guideFinally, there are the 620 film cameras, which include such gems as the Medalist and Chevron series. This is the easiest of all, because the 620 and 120 film sizes are identical. Only the spools are different. I got your back.
https://www.uglyhedgehog.com/t-616725-7.html#10636704Some of the cameras in these formats are among the most iconic and pleasurable cameras ever produced. In my (not so humble) opinion, it's worth the effort to enable shooting with these wonderful cameras. No, you're not going to "spray and pray", but you might enjoy taking deliberative shots and getting in touch with an earlier age. I hope at least one Hogger reading this takes my advice to do so.
Andy
PS: I can't help with 110 or 126. If you bought a high end camera in one of these formats, you are really limited. And "peel apart" Polaroid films seem to still be waiting for sufficient demand. But if you've got a high end shooter in 127, 620, or one of those huge roll film formats, it is worth a try, at least in my opinion. There is so much pleasure to be found in shooting quality vintage gear.