Ebay listing for this is here:
global.ebay.com/BULOVA_SUB_SECOND_WINDING_VINTAGE_USA_MENS_WATCH/270640254628/item
The date stamp on the movement shows 1948. The listing describes it as a "Sub Second" Model, 21 Jewels, 7AK movement
CASE DIAMETER
: 23mm with crown
CASE SIZE LUG TO LUG
: 37mm Lug to Lug