As a new hobbyist working on my second movement, I made a rookie mistake. In opening the mainspring barrel, the arbor was really holding on to the spring, and when I popped the lid, the mainspring exploded out.

My first option/preference would be to purchase a new/replacement mainspring, but I can't find one for a Waltham 1802 series. That is the number stamped between the lugs as well as on the movement base itself. The inside diameter of the mainspring barrel is 9.0mm, the depth of the...

Mainsprings and Winders