1957 Bulova Senator “H”
SN C631857 on a Stainless Steel case back
L7 date code
17 jewel 11AC movement with L7 date code
1956 ad in the pictures
crystal measures 23.1mm x 18.7mm
The crystal is square when viewed from above.
It is domed crosswise as well as top to bottom.
The underside of the crystal is arched on all sides.
The case does not allow for a crystal that is flat under any side.
While the illustration in the 1956 ad is poor, it’s sufficient for identification by comparison.