In reply to Hi Jim - I assumed you did a by Geoff Baker
Stamford case, but with engraving on the bezel uprights.
Seen before, but no matching ad.
Stamford and Alderman in red gold case have 17 jewels.
Case SN gives a date of 1946.
'1946 Unknown.'
Edit- Possibly the Aviator "B", correct case/dial/hands/jewel count, just not enough detail to show any engraving.
Although, looking at the lug tips,t does look a little like engraving, especially to the top right lug. Can be seen a little better when magnified.
Question:
Why are the lugs on the right side of the picture of the Aviator "B", which are in the light, not shiny like a plain lug should be?
Answer: They are engraved, that's why!
The ad is a mat picture of an actual watch, not a drawing, we can see the left side is in shadow, so the right lugs should look "plain" if they are plain.
Here is another ad for the same watch, this pic is taken from directly above.
Why are the lugs not shiny like the bezel?
Engraved.
In my opinion anyway.
Here is and ad for the yellow gold Stamford, same case.
Shiny plain lugs. 17 jewels. Look at the Navigator on it's right. engraved lugs and bezel, dull.
Remember the Commando?
A Lexington with engraving.
http://www.mybulova.com/watches/1946-commando-2480
Same kind of thing going on here.
Another example with fifteen jewels here: http://www.mybulova.com/watches/1945-unknown-2008
So it's not a movement change, same 10BC.
The Aviator ads are from 1948 top, 1946, bottom.