Happy holidays everybody, I have a question about a South Bend watch that I bought the other day ,It is a grade 211, 17 jewel, model 2, size 16. On the barrel bridge there is a screw that has a curve shaped arrow beside it. What is the function of this screw?. Also need to locate a balance staff and possibly jewels for this watch. All replies appreciated. Thanks, Gary.

Hello Lindell, Thank you for your prompt response and the link. I haven't seen this feature before. Gary.