Found this today and wondered what you thoughts are.
The mechanism has 1100 marked on it beneath the balance.
Attachment 1574505Attachment 1574506Attachment 1574507Attachment 1574509
Movement looks like an ETA 1100, hands and dial give the watch away as an early to mid 1950s' piece. The case looks to be all steel (which would speak for an expensive watch back then), but I cannot say for sure: check the lug edges for wear - if there is a different material underneath the case is only chromed (which was cheaper back then.) What would be funny is that B&M would use the ETA 1100 in its lowest-jewelled variant - according to Roland it was available with 15, 17, 18 or 21 jewels. (A higher jewel count does not necessarily make a movement better, but 17 was actually middle class standard in the 1950s.)
I'm a bit unhappy with the dial which looks like someone has brushed it up a bit. A genuine one (to my opinion) is showing on this watch which fits about the same time period - late 40s/early 50s.
I'm no expert, but the People at B&M are. According to the only reply in this thread they are quite responsive. Turn to them with the serial number from the case back and see what they reply. Good luck!