Bulova 1946 Cadet "D"
Just got this one; and the outside was so crud dirty that I couldn't see the engraving around crystal. By process of elimination, I believe this is a 1946 Cambridge. It was quite a surprize when the exterior cleaning was complete, and case and face are nearly flawless. A couple little marks in crystal. Wound it up and although the movement is filthy, it's keeping excellent time.
Referenced ad is about 5 years prior to watch date, which may account for the difference in the second hand subdial track.