hello i found what i 95 percent is a duowind..only selfwinding is under the bulova name..i think i have seen this before but can't be sure..i can't be sure its says selfwinding,but i think it does..didn't some say selfwinding and then duowind above the sub seconds? the picture has a glare right on the dial and the crystal is beat up too...so its hard to read...anyway i know its a duowind case,which is rare enough...i checked the ads and only duowind was the round one.in the ad there isn't anything shown on the dial,since the artist just didn't drawn it on...i mean its a duowind case i am pretty sure its from the original owners family who is selling it..i going to buy it anyway since i only paid what comes out to 18 dollars for it and it is rare..but i was just wondering
Can't say for sure without seeing the movts, but I suspect the Duo-Wind was a bi-directional winding movt, (Felsa) and the ones marked 'Self Winding' could be another automatic calibre, with unidirectional winding. I could be wrong, perhaps it was only a name change. I have later model Bulovas with "self winding" that are bidirectional, but they are much later. My thought is that initially, "Duo Wind" was to differentiate from the AS bumper autos prior to this that were unidirectional.
Examples in the archive marked "Duo-Wind" are all Felsa Bidynators, with the exception of two AS 1320 series. Also, "Duo- Wind is a model, whereas "self-winding" is a feature? Fifth has a tank version here, with 9AB (Felsa 705):
There are a couple of examples in the database of a tank style Case wearing the 2 different insignias.
One Dial is marked 'DUO WIND' the other 'selfwinding', both Dated differently. The latter of the 2 has been ID'd by ad and has a Name, but I can't find it at the Moment.
IMO a Bulova Dated between 1950 -'52 and signed 'DUO WIND' on the Dial is just that, post 1952 they begin to take on individual Model Names. it seems.