Bulova Factory Mainspring for caliber 10AK & 10BM made for military - Steel

Bulova Factory Mainspring for 15j caliber 10AK & 10BM military issue watches, steel, sealed in bag. These were distributed specifically to the US Military in packaging (and part numbering) for late, post WWII, Bulova Military watches (these are from 1946). This shows a Stock No of F36-7198154 but it should read F036-7198154. Described in parts catalogs and on the tag as "Spring - main assembly" and have the Dennison characteristics 4 x 11 x 11¾ or thereabouts and thus fit more calibers than just the 10AK & 10BM. These were packed and sealed by hand so each of them looks a little bit different - they were actually packaged in Purolator packaging made with oil. I specialize is hard to find watch parts so I usually have whatever you might need and all watch parts are unconditionally guaranteed. Images do a marginally adequate job of representing the item.