Pocket cal 37.6 S.15P

Hi,

Need a bit of assistance here. I have this cal 37.6 sonette design pocket watch. Was not working to start with and I found that the impulse roller came loose (previously glued on instead of tight fit). The hairspring condition was not good as well. I tried to glue back and adjusted the hairspring but cannot get the watch working. I suspect the alignment of the banking ruby likely out of order.

I have two options. One, go to an experienced watch repairer and hopefully can get it sort out. Second, look for replacement part (balance wheel complete assembly - wheel, hairspring, balance staff and roller). This is where I need a bit of help. Scouted the web and cannot figure what's the equivalent for replacement. It's hard to find cal 37.6 balance replacement. How to spot the equivalent balance wheel for pocket watch? What other cal using the same balance? Is there a table to check? Anyone here can point me to the right direction?

Thanks!