Interesting 1959 Bulova "23" in white gold RGP with snap on stainless back. Dial is a silver/charcoal grey and has a pattern like the grooves in a vinyl record. Band is a period Baldwin scissor replacement. I haven't attempted to open this one up for fear of damage. Does not show any evidence it has ever been opened.
I have included a 1959 ad snippet that appears to be the same watch although it makes no reference to dial or variant; just "new ultra-thin".