Not much doubt what this one is. Yellow gold plate with white gold engraved frame around crystal. It appears that in the "B" and "C" engraved variants this face was interchangeable with the fully numbered face seen in ads for the "A".
Spring release is crisp and snaps open when clasp is released. Mounted on a replacement black alligator strap. A really sharp example of this variant with little sign it was ever worn. I have a feeling this was more of a keepsake item than daily wear. Keeping excellent time. Period photo of a majorette added by me as a stand in for Betty.
1950 Photo Watch "C".