Brass Dennison & Millimeter Watchmakers Mainspring Gauge

Brass Dennison and Metric Mainspring Gauge, well used but in good condition. Marked "Made in USA for" and then nobody is specified underneath.  Once side is Metric and the other is Dennision. Previous owners name are engraved on front of the tool. Tool is pretty good quality and still in completely functional condition given it's probably a good 100 years old. Images do a marginally adequate job of representing the item.