This is fascinating stuff. At the time, water resistance had become an intensely sought after attribute, and the Borgel patented screw cases had been sold since 1906-07. Rolex used these same cases for a limited run in 1922, and produced the oyster case in 1926. The Borgel wristwatch cases were invariably always pin set due to the screw in design of the carrier ring and movement, so designers were looking for a way to have a stem set watch with similar sealing attributes.
Clearly, in order to protect the watch movement from the elements it was necessary to have a sealed case and a screw down crown. This is true today, and this watch shows both attributes. It also bears a strong resemblance to the Hamilton 'Piping Rock' watch, introduced in 1928, but the Piping Rock had no such water resistance features.
It's hard to say who produced this case for Bulova, but at the time various companies were working together to produce this type of watch. This may have been a limited commitment, as it does not continue in any Bulova model, so that may explain why there are no marks we are used to seeing.
At the time, stainless steel was more expensive than gold, and companies were trying various manufacturing methods to produce a case that was rust and tarnish free, especially in watches that were to be used outdoors or for 'sporting' purposes. Unfortunately, this type of chromium plate over base metal (often zinc based) was prone to pitting and corrosion.