Broken staff question on a Waltham model 1883

This watch is my first attempt at learning pocket watch repair. Got it pretty cheap at a farm auction and it looked pretty nice and appeared complete.

Replaced the broken "dumbell" spring thanks to Dave Abbe for the part.

Since the balance wheel seemed too wobbly, I was thinking it had a broken staff. Bought some movements on e-bay and tried to use the parts, but they all seem to bind up in some way or another. Are these staffs made to fit the individual watch? Where do I go from here ?
I'd be completely lost without the help of this group.
Thanks, Don

Until the more knowledgeable appear, the best I can tell from information to hand, is that the 1883 seems to utilise either #1364 or #1365 Staff which is ~5.85mm and available in pivot sizes 10 - 15. The #1365 has a small waist.

Thanks for your help Gareth.

Don

Finally got home and checked Swigart which states #1365 for U, A & P Grades but no pivot size info. Hope you manage to get it sorted out.

Donald, The Model 1883 seems to have had many "small" changes during it's 40 odd years of production. Many of these confound us in their little inexplicable "deviations". One(for sure) is the end-play dimensions for the balance staff. In short, to fix this is not really a "beginner's course", I would instead refer to it more often as the "beginner's curse" . . . both figuratively and literally.

Thanks Gareth and Dave. I'm finding out that the mod. 1883 does have it's quirks.
Thanks for the help.
Don

What area of this balance staff is considered the "waist"?