There is not a square date code. To me with loop it appears to be a triangle (1926?). I see several octagon Lone Eagle watches after the June flight. I also see in the old dated ads here listed with the tonneau shape as “Lone Eagle” . I read the history of the challenge to aviators from Bulova which raises yet another question? Are the specs on the watches sent to aviators catalogued at Bulova? The case number ends with 27, along with the patent date but not the movement code. The watch winds and runs and keeps time accurately for approximately 10 hours within one minute. It became a tight wind after being wound 10 times. I did not push it further, although I repeated this a dozen times with the same results. The dust cover is yellowed but intact. It is apparent that at some point a sloppy attempt to open the case was at the hinged end with some damage apparent. My takeaway is the watch deserves a day at the spa. The movement may be from 1926 and the case from 1927. The movement number looks early ending in 005. I can’t assume it is between Jan and June of 27 yet maybe possible with the research parameters available to me. I thank you for your time and look forward to your response.