An interesting attempt at water resistance, the bayonet bezel rotates and locks into place. Two piece split stem, and regular water resistant crown with gasket. I won't be undertaking the restoration of this one til I get some more time, but I thought it interesting enough to post so we can all get a look at it.
Stamped 'N0' on the movt, but 'M0' inside the case, and this is an indication of a much later movt being placed in this watch. The depth of the case is insufficient to allow for an automatic movt, so the one that is present, the 11AFC, handwinding, is probably close to being correct. Swiss made case, and dial made by Durig Freres of Bienne.
A typical hazard for this series was the shearing off of the dial feet, when rotating the bezel to remove it for service. This has happened here, and we will be laser welding the feet back on, and while we're at it, will be refinishing the dial.
The watch is from a Montana Watchmaker's estate.
*Edited to reflect change in date of manufacture from 1970 as originally posted to 1960.
Flanged crystal, yes. I'm going to agree with Mark's comparison with the other 1960, the cases are obviously the same basic design. I originally thought the 'M0' was 'MO', but I am going to go with the date of 1960. This would mean the movt is a replacement, and it is also possible that it originally was an auto. I'm going to take some measurements.
So colour me 'Unknown 1960'.
In reply to Flanged crystal, yes. I'm by Reverend Rob
It will be interesting to figure this one out, I would bet that the crystal for the case will turn out to be a generic swiss branded, or possibly a known swiss case maker with the markings, when you get a chance, measure the flange & step, and I will do some catalog searching, none of the Bulova listed crystals have the eased corners like this one, they are all square corners with a square flange.
In reply to The depth of the case is too by Reverend Rob
Stephen, that's the crack in the crystal, it's pretty much dead centre.
The dimensions are certainly close, Greg, would probably fit with some adjustment, and has a nice dome to it by the looks of the package. The one I have is flat. I'm just checking with some sources to see if I can find an original.
Updated description to note that the case is shallow and could not have accomodated an automatic movement. Also the dial is made by Durig Freres, Bienne.
Just to be sure about the dimensions, as it was possible my info was incorrect, I attempted to fit an 11AFAC in it, and it doesn't even come close.