I am not sure of the year of manufacture.  According to the list on this site, the cresent moon could be 1928 or 1938.  The case has a patent date of Jan 11, 1927.  There are some other numbers scratched into the case that I suspect may be from repair shops?

Heavy engraved 10k rgp case and stainless back, Butler finished dial.  Measures 26mm excluding the crown and 38mm lug to lug. Best Philip 

"Bracelete watch". Bracelete articulada com corrente de segurança e 2 brilhantes.

MOVIMENTO: Bulova 5ADJ. 21 jewels

ESTOJO: Original Bulova "American Girl"

This Senator sports is one of those rare double stamped movements.  It shows Omega and Asterick for 1940-41.

The natural gold color case is in excellent shape.  The salmon/rose colored dial is in poor shape and will need a redail.  I have a Senator with this dial but a rose gold case so I'm wondering if this case isn't a replacement ?  The contrast is a bit different after seeing the one I have but not wholely unpleasent.  Though with a redial needed anyway this could in fact be a good candidate to make it match up a little better.

1930 was a big  transition year for Bulova. Without a doubt Bulova watchmakers had to do comparative analysis to determine cost & manufacturing efficiency & reliablility of their current & future products. During the late 1920s Bulova had great success with the circular 10AN caliber movement.  The 13AF movement was specifically designed for tonneau & rectanglular shaped cases. Normally, Bulova minute track & seconds chapter outlines are shaped to emulate the shape of the case.  This Lone Eagle II series watch is uniquely different from the Lone Eagle II powered by the 10AN movement  Notice the dial with the rectangular shaped minute & seconds chapter outlines and short stubby cathedral hour and minute hands.  The case frame was made quite different in order to accomodate the 13AF movement. This is not  a one-of-a-kind-watch.  There are at least three of the 13AF test bed watches on-site. The 13AF is apparently a very fine movement, but it didn't make the cut due to number parts & complication of assembly. Note the picture of the disassembled 13AF in Image 6.  It is conjecture on my part that if the 13AF movement had been accepted & used in tonneau & rectangular cases there would have been no need for the step-side design watches of the early 1930s.