Another of my "what the heck is that" purchases. External serial number is only 6 digits long. Based on not knowing if s/n is missing a digit (either first or last) I dated it by the movement. Outside marked "Bulova" on s/n end and "10K rolled gold plate" on other. No markings on inside of the single hinged case back besides a scattering of jeweler marks. Movement has a date code for 1934.
Case is 2 tone (yellow gold top w/white sides) and watch has a matching 2 tone band as received, with "Jimmie" engraved on clasp. Mismatched seconds hand.
When received, it would only run face down. I wound it and let it sit face down for 23 hrs and it kept time. At that point, I wound it again and flipped it over. it now runs and appears to keep time face up on the wrist.....weird. Does not appear to have seen much wrist time.
My best guess is 2 tone Commander variant. Whatever it is, it appears to be a first for the database.
What I think you have is a 1934 Bulova Cavalier. This is from our Ad archive from 1934.

In reply to What I think you have is a… by JimDon5822
Good call Jim, I agree. The only other example of Cavalier in the database also has a 6 digit s/n starting with a "9" and a 1934 date code on movement. That one appears to have a swapped dial and replacement band. It looks like Cavalier pre-dates Commander.
1934 Cavalier works for me. Well found!
In reply to Good call Jim, I agree. The… by neetstuf-4-u
It appears that by 1936 the yellow gold model has been changed to the Commander based on the ad we have from 1936.
In reply to It appears that by 1936 the… by JimDon5822
Yup, agreed.
Nice two tone model, congrats! Good ad find Jim.
1934 Bulova Cavalier
Beautiful watch Bob 1934 Bulova Cavalier