I have an L4 Bulova 23C and a L6 Bulova 23B, both with 10BPAC movement.
I want them serviced, but my 'service-guy' always wants to replace the mainspring when serviced.
Since the 10BPAC is an Bulova inhouse movement, spare parts are really difficult to find in Europe. (Holland).
I understood on this forum that 10 BPA, 10CBAC, 10BPAD can be used.
If you have one (or two), they come in a barrel, or you know where to find one, this would be really really helpfull !
Thank you in advance, Sybren