I have a picture of a similar model 36mm case with cal. 453/3B, but the caseback only shows a serial number and not a reference number. That, style/size of the piece and the case number suggests the early to mid 1950's. A few years later that caliber was used in the so-called XXL 38mm models. Yours is really stunning...those applied numerals are sooooo tiny and delicately placed on a flawless dial. A tip of the hat to you, sir!