What is the age of this Ball case? It is marked Ball "Official RR Standard" keystone 10k g.f. #9827789.

It currently has a Waltham Crescent Street movement in it, and an extra set of screw marks.

I am thinking since it has the shoulders flanking the winding stem it should be for a earlier Ball Movement? But which one...

Thanks for any help.

Back of case. Should clean up nice.

Back showing the movement and extra screw marks.

Looks like a nice case Keith. The highest quality later Ball-Model cases which we often find housing 998-Elinvars and Ball-Illinois movements have "shoulders" such as you are showing. I would say very late 20's to mid to late 30's would be the age of your shouldered case.

regards,
bb