LeCoultre went into full production around May of 1939.
The above dates and serial numbers will give you a reliable
way to date any Atmos. Please realize that this is not an
exact list because LeCoultre did keep some serial numbers
for certain calibers and they tend to jump, so there is
some overlap but the above is about 98% correct.
The guess on the 2000’s and up is because all the dates
are based on my overhauls of the Atmos and I simply have
only overhauled a few made after 1999.
Now for the specific dating information I offer.
The following Acrobat file contains some of the Atmos clocks
I have work on, listed by serial number. After the serial number is
the date that was found on the bellows.
The bellows were made in batches, so there is some duplication but
more than enough information to date your specific Atmos to within a
month or so.
All I ask is that you reference where you obtained this information
if you use it anywhere on the Web including sales or auctions.
This file contains some of the serial #'s of Atmos clocks that I have
repaired that still have had the original bellow intact.
The serial numbers are located on top of the movement next to the
fast-slow adjustment. On some early caliber 519's and the Atmos II´s
the serial number is located on the bottom of the movement and you can see
it through the front of the case.
The caliber's from the 522 to the Atmos' made today are stamped,
with the particular caliber #, on the bottom of the case. The Atmos II
and caliber 519 were not stamped on the bottom and are nearly identical.
You can tell the difference because the Atmos II has the speed adjustment
as a turn screw rather than a slide lever, which is found on the caliber
519 and all models since.
Estimating the value of your Atmos
My "stock" answer for valuation is to go to eBay.com.
Click on search. Once in search type in the words Atmos clock and
leave the category box checked as all categories. Check the search
title and description and check completed listings only. Then
proceed down the page until you see the Search icon and click that.
There you will find the last 30 days of closed auctions and
you might find a few that are like yours or at least similar. In general,
a serial # around 50,000 above or below your serial #, will give you a
similar Atmos for valuation purposes.
Please keep in mind, that LeCoultre totally redesigned the Atmos
in mid 1983 and therefore any Atmos with a serial # under 600,000 is now unique.
I not an appraiser and don't like to give valuation. Ebay is by far
your best research tool and the best place to sell it for the best price.
For information about my Atmos overhaul, please see this page: