Waltham Factory Mainspring for 18s No. 2201 - Steel

Waltham Mainspring for 18s Model 1857 movements, Factory No. 2201, Single Brace and Hole, Steel, new in frail envelope. See images for further details. These can be pretty tricky to find. Mainspring has been in the shelf for probably close to 80 years but I inspect all these steel mainsprings carefully before I list them, and I guarantee them unconditionally. Images do a pretty good job of representing the item.