Do the 3/4 size machines hold as much thread on the round bobbins as those on full size machines? Again, many thanks for all your expertise! I promise I'll let you all know what I end up buying. I seem to be narrowing this search down a bit. Definitely decided I want a round bobbin, not a shuttle (at least I've figured that out, lol!) I'm considering a a Red Eye Treadle and a Singer 3/4 size 15 treadle right now.