I Have this 1958, but I need to pick up a mainspring for it which types are interchangeable? 10 BP, 10AC, 10AX.
1959 - 23 Jewel
1956 - 23 Jewel
I have 2 BULOVA 23'S that are L4 (1954) and both have 10 BPAC movements. The only diffence between these units and the one pictured is that they do not have the "6 ADJUSTMENT" and adjustment descriptions imprinted. I know for sure that the case back on one couldn't have been switched, as I received the watch in May, 1955, for HS graduation which surprised many!!!!
Found in a 1956 "Bulova 23"
Added to database 10/29/2011