Movement is also stamped Bulova Watch Co. "AAA" USA.
Case is stamped "B-10K Gold Filled"
I'm thinking this is an Ambassador A but I'm not certain.
Thank you for any help!
Hi Bsshog40. Nice Bulova you have. I'm not certain which model it is either. All the 1939 ads I've found show the Ambassador has the 21 jewel movement, but in a 10k rolled gold plated case. The 1939 Montgomery and the Oxford which look similar are shown to have a 10k gold filled case, but with 17 jewel movements. Now; I just looked at the case serial number on yours and it starts with a "0" which would indicate a 1940 model. Let me do some more searching. Maybe something changed in 1940.
In reply to Hi Bsshog40. Nice Bulova you by 1955mercury
I'm getting closer. I found this 1942 ad showing the Ambassador with a 10k gold filled case and the 21 jewel movement.

Looks like a match. Ambassador "B".
Looks like an ad match to me.
Ambassador "B". Nice watch, good ad find.
Awesome guys! Thanks a bunch!
It also runs very well. Is it hard to find original bands and pins for these?
In reply to It also runs very well. Is it by bsshog40
It will probably be difficult finding an original band unless money is no object for you. Your best bet is to get a leather band and manuever it over the curved lugs on your watch. The pins shouldn't be a problem to find.
Ambassador "B"
So when I look at the bulova's by model, it doesn't show an ammbassador in 1942, but does in 1940. So this is actually a 1940 Ambassador B correct?
In reply to So when I look at the by bsshog40
The case on yours is a 1940. We can determine that by the serial number starting with a "0". The movement should have an omega symbol or a shield symbol stamped on it if it is original to the watch case. The ad I posted is from 1942 because that is the closest one I could find that matches your watch.