4/0 6/0 8/0 10/0 16/0....etc is the size. 10/0 is pretty big. They were good reels in their day and still are for fish like shark. The newer equipment has made these obsolete. The old drags really can't take a big run of a large tuna although I remember as a boy landing 100# class fish on them with my dad and uncle off Montauk (not that I catch that many each season anymore)
After posting this I went up to the fishing attic and took them out of the box and placed them on my fishing bookcase among all the books...they look great there. I am sure they will trigger lots of stories. After holding them I think I will keep them where they are just for sentimental reasons. Cranking the handle you get the feeling you are Capt Quint in the famous "Jaws" scene when they focus on the same reel with the loud CLICK CLICK CLICK....
. The line on there is a heavy dacron...the "braid" of the day.