Manufacture year unknown. Please help.
Welcome to My Bulova. We'll need caseback markings as well as movement information. The case opens with a case knife, you will see a protrusion on the stainless back to pry them apart. Be careful. Use a dull pocket knife or proper case knife. If you are unsure, take it to a watchmaker.
Early 40's Minute Man?
Still looking.
Case serial number starting with a '0' would suggest 1940.
1940 'MINUTE MAN'
ad is '40 http://www.mybulova.com/sites/default/files/vintage_ads/Bulova_AD_1940_4.jpg
If it is a 1940 I would agree that it's a Minute man.
Good advert match. 1940 Minute Man it is.
With the new ads I think we rename - Midshipman

Agreed. I found enough ads to document this watch as a Midshipman.
Was there a model name change from1940/41 to 1942/43?
The 1940 Minute Man advert is also pretty convincing and ties in with the year this watch was produced. The Midshipman might be the later 42/43 version after a name change.
I think this should be a Minute Man for 1940 ( I still do!)