Waltham Factory Mainspring for 20s Model 1862 No. 2200A - Steel

Waltham Factory Mainspring for 20s Model 1862 movements, No. 2200A, Steel, new in envelope. See images for further details. These can be pretty tricky to find - ok, really tricky to find. Mainspring has been in the shelf for probably close to 80 years but I inspect all these super old steel mainsprings carefully before I list them, and I unconditionally guarantee them. Images do a pretty good job of representing the item.