Came to notice the Swiss Poincoin mark on the cases. (The hammer head mark with a number in it.)
#140 B. & C. Dubois Le Locle 11.07.1934 09.12.1947
From what I can make out of it, the last date (Radiation) is the date the company went out of business.
This would again help determine a relatively precise year of manufacturing for the watch cases in question.
Source:
https://www.vintagewatchstraps.com/swisspdm.php
Hi
@Northernman
On these Lemania, and several others in gold from Lemania, the hammer head mark with a number in it, the number is 105.
So the casemaker was:
Les Fils de Jules Blum, from 11.07.1934 to 16.05.1974.
Based on that assumption, I presume it will not be so easy to date them.
For the chronometer model, seems to me, there was two types of case.
One with larger lugs, on case serial 20400 and 20433, and other case with thinner lugs on case numbers 20547, 20531, 20527 and 20552.
Even so I am finding extremely difficult to date them, as per my research.
Movement serial number 21176, has the case number 20547
Movement serial number 21233, has the case number 20531.
So I found no logic on sequential case numbers, has a lower serial number movement, has a higher sequential case number.
I will keep digging.
Thanks,
João