Not sure if this has been answered or if anyone has observed this before but I have noticed some date code oddities.
I have a couple hundred movements I didn’t get around to adding to my data base. Worked on it over the weekend and saw several 1927 movements with a broad arrow marking. I am not talking about late movements that are “USA” marked but early movements. Off my head I remember a 100,xxx or 101, xxx 6AF with a triangle and a broad arrow date code. This should be a 1926/1927 movement and odd to see a 1937 date code. I also distinctly remember a 210,xxx 10AN movement with a square and a broad arrow marking. Agin, this is not from 1937, should be a movement you would expect in a 1927 Lone Eagle or a Banker.
Second point is a Diamond marking, not a square on edge but an elongated mark that is obviously narrower than what you would see in a square marking.
Assuming which is dangerous but thinking Bulova started using the broad arrow mark in early 1927 but for some reason changed to a square. Also believe the diamond I observed is early 1923-1926, saw it on earlier movements based on serial numbers.
Third point isn’t necessarily dating but going through a couple dozen AAI movements I just realized there are many sizes, just the few I checked were 10 1/4, 9 1/2, 9, 8 3/4, and 8 1/2 Linges. Need to upload all the data to an excel I have then pull out the other AAI movements to get exact measurements. Never noticed the difference until I had an 8 1/2 sitting next to a 10 1/4; at that point I noticed the difference.
Thom, you've raised a very interesting point.
The notion that Bulova re-stamped a number of their early 1927 watches that where actually manufactured (and stamped with a triangle) in 1926 has merit.
I have always wondered why the original LE 5000 watches had this arrow (see 1937 date code) as well as a traingle (1926).
My thinking here (and it aligns with what you have said above) is that Bulova used watches manufactured and assembled in 1926 but were put to market in 1927 and as such re-stamped the movements accordingly with an arrow, which as you say may have been the original date code before they switched to the square (1927).
This, to my thinking, would have been done very early in 1927.
It is a great theory, one I can get behind as it does explain the 1927 Bulova Lone Eagle that I consider to apart of the 5000 batch. Bulova (I believe) had these all set for 1926, but then needed to re-stamp over to 1927 when nobody had managed to complete the transatlantic crossing.
