This watch seems to resemble posted examples of the HE"B", but is a 17 jewel with no case engraving and a plain dia. Watch appears to be all original with dial in original state of finish. Band is a pigskin leather replacement. Stainless steel back. Both movement and case dated L1.
You're right, there is a definite resemblance to the case and dial of the HE 'B'. I don't see this case design in other ads, and I wondering if perhaps due to the lack of bezel engravings and non-21-jewel movement that it is another model name. I'm going with 1951 Unknown at this time.
The Senator in the ad appears to be this model. Also, notice the font of the number 2 and 4 markers in the ad.
In reply to The Senator in the ad appears by Andersok
In reply to Hmm you are correct, the lugs by mybulova_admin