c1930? Enamel case w 1927 Pat Date caseback 10AN 21J 6Adj no date symbol
Movement: 10AN 21J 6 adjustments, w/o date code/symbol or SN
Inside Case Back: Bulova Quality Pat. Jan 11 1927 SN 1127945
Outside Case Back: Open
I'll go look around the ad's to see if I can fine this or similar model. Case is crisp!