1957 (L7 - both case and movement) Bulova 23 "S" with original Blue Box
the crown is unsigned, but fits absolutely perfectly on the watch. I don't know how to tell if it's original or not.
1958 Bulova 23 "S", similar watch
I agree, that is the Bulova 23 'S'
Agreed, Bulova 23 "S"
One difference to note between my watch and the one pictured in the ad is the length of hands. Though other Bulova 23 "S" in the database also have shorter hands - more similar to the watch pictured in this ad: http://www.mybulova.com/sites/default/files/vintage_ads/bulova-ad-1958-…; - yet, that one has cross hair dial
Looks like the '23S' to me, hands may have been replaced, but the watch is fairly pristine, so not likely. I don't think it will affect the ID.
23 S gets my vote.
After I saw the second ad, I realized that when I picked up the watch, it (most likely) had the original band - same design as the one in the ad. Honestly, I was about to throw it away, as I really don't like such bands, but I'm glag I did not.