Tentative Bulova Astrojet
Stainless case with champagne color dial with Bulova and Astrojet printed; caseback is stamped M3, #398-1, MLB manufacturer. Movement is an 11AFCD 17-jewel manual wind with the calendar window, dated M3.
No ads have been found for this model and this model is not listed in any pricelists we have, though no pricelists are available for 1963; the case catalog does not have this case number listed as being excluded from US sales.
Benrus trademarked the name Astrojet in 1961 for watches, and American Airlines in 1963; perhaps Bulova had to stop using this model name and then moved to something else like Aerojet, which is a very similar design though not yet seen prior to 1966.