On a garage sale I bought an old metal LP worm. Remember those things we used to put our record albums in? Anyway it's marvelous as a ruler holder. I bought a similar but smaller letter holder one for my small rulers.
When the set screw on the small belt/motor wheel broke out of my vintage Singer I cut a very small (about 3/8") piece off a bamboo skewer, stuck it in and have been sewing with it in there ever since with no problems.
I use a 20" sq of styrofoam and made a little fitted sheet for it out of flannel for a block layout board. I set it on an easel right by my machine. I only use it if the blocks are large and tricky---like the ones in my avy.
Best yet: I have lots of machines so if one goes on the blink I just pull out another one. NEVER be without a back up machine.