HistoricTimekeepers Restoration Services and Supplies

To see images full size right click and select "view image" or "view image in new tab" Depending on browser




HTI Main Page
Hamilton Elgin 37500 Elapsed TIme Clock
A-6 A-7 A-9 Aircraft clocks
WWII German clocks
Waltham CDIA
Waltham A-13 and Mathey Tissot Type 12
Jaeger LeCoultre A 10 (Chronoflite) Elapsed Time Clock




Popular Highlights


Notes for Young Watchmakers

HTI Approach to Service

Microscopes in Watchmaking

When only a watchmaker will do

The 37500 Contract Prototype

Restoration of Omega Jump Seconds Clock

Shop Tour

Photo Series Index Page

Warbird Clocks for Sale

Equipment for Sale










WWI USAAC Issue LeCoulter A-10 Chronoflite                       WWII  Jaeger LeCoultre Aircraft Clock

Warbird Clocks


REstored WWII Waltham CDIA Aircraft Clock                                  WWII USN Waltham CDIA


REstored WWII Hamilton Elgin 37500 Aircraft Clock
WWII Hamilton Mod 37500

This section describes the WWII Aircraft clocks sold by Historic Timekeepers, Inc. and the process used to restore them.  This process also applies to ALL aircraft clocks restored in our facilities.

All timepieces (sold or serviced) are delivered only after complete disassembly, replacement of damaged parts, mainsprings checked/replaced/lubricated, all parts lubricated and adjusted as directed by original instructions (or as by superseding instructions), all functions checked and the completed movement is test run for 1 week after the last adjustment.

NOTE:  We have the only stock of brand new stainless mainsprings for the three major WWII clocks: 37500, LeCoultre/Smiths Chronoflite and Waltham CDIA.

Parts are not "patched".  They are either replaced or made; every clock sold by HTI is "as new" with the exception that some knobs may not be exact replicas.  If we encounter a clock that is simply too costly to refurbish, it is cannibalized for parts that will replace damaged parts in other clocks. For example, we stock or make balance staffs for every model aircraft clock.

Some aircraft clocks, like the Jaeger LeCoultre Chronoflite or the Elgin Hamilton 37500 Elapsed Time contain nearly 500 parts.  All clocks  MUST be fully disassembled.  Many have been unused in uncontrolled environments for 20 years or more.  All old lubricant must be removed and all hints of rust must be found and rectified by either parts replacement or reconditioning.  Many of the steps involved can be found on the pages for Aircraft Clock Restoration and Repair Services and on the pages describing the individual models offered for sale.

Clocks for Sale.

The combination of interests (passion?), micromachining skills and expertise in precision timing provides Historic Timekeepers, Inc. with unique opportunities to serve those whose goals include maintaining vintage military aircraft (and civil aircraft).  Over the years we have made it a priority to buy stocks (small and large) of parts and clocks from repair facilities that left the mechanical instrument market.  We actually pride ourselves on being the last of the buggy whip repair shops!

For some clocks we have stocks of parts that have been in military deep storage for nearly 60 years.  Of course these are mostly the American instruments.  For many foreign military clocks like the Junghans 15 minute elapsed time clocks used in the ME 109 or FW 190, or the Seikosha chronograph used in the JIN aircraft, we either make needed parts or have a stock of "donor" movements that we cannibalize.

The factory service instructions for many of these non US clocks are simply not available.  However, physics knows no nationality.  The lubrication and adjustment of parts for correct function follow industry accepted practices.

We try to stock the following clocks in ready-to-fly condition.  Please contact us for more information after you review the description of the clock(s) of interest.  We will try to keep these pages current but the weakness of online catalogs is the time required.  If you have a requirement not addressed, please email or call.  By the way, these pages were updated July 2007.

In our own small way, this is our effort to help you "keep 'em flying".

While not for sale, this clock may be interesting to examine.

Preproduction 37500 in Lucite Case and Skeletonized Dial

Rare view of Preproduction WWII 37500 in Lucite Case



 Elgin/Hamilton 37500  WWII Hamilton Elgin 37500 Clock for Sale



   Jaeger LeCoultre WWII Lecoulter Lecoultre A-10 Chronoflite clock for sale


     Waltham CDIA  WWII Waltham CDIA Aircraft CLock for sale


WWII German clocksWWII German ME 109 Aircraft Clock for Sale


Other WWII clocks  WWII A-10 Aircraft Clocks for sale   


Mathey Tissot Type 12 Waltham a-13-a chronograph aircraft clock for sale









Waltham A-13 and Mathey Tissot Type 12 

Important points.  All Aircraft Clocks are accompanied with a Certificate of Performance that documents the performance of the timepiece after restoration (the same COP that is provided for precision watches and navigational timepieces serviced by HTI).

  Unless otherwise noted, carbon steel mainsprings are replaced with new "unbreakable" stainless steel springs.  This serves two purposes.  First, NO timepiece can yield top performance with 60 year old springs.  Secondly, the use of 60 year old springs (no matter when installed) results in extensive damage when they break.  This is especially critical in clocks that use two mainsprings, such as the Elgin/Hamilton 37500 Elapsed Time Clock; the Waltham CDIA .

  All timepieces are warranted for performance for one year.  

  Timepieces serviced and sold by Historic Timekeepers, Inc are suitable for use in exempt aircraft and for collectors.  It is up to the Chief Operating Pilot to determine if additional FAA requirements need to be fulfilled for use in non-exempt aircraft.  It is noteworthy that Northrop-Grumman and Flight Safety have used our services for their simulator instruments and the US Navy has used us for navigational timepiece service (Ship Chronometers).

ATTENTION!  This year I several received requests to make corrections to several aircraft clocks under warranty.  I would have done, except the work was not mine.  Apparently there is someone very active on eBay using a similar sounding business name and a website that is similar in layout to mine.  While I am flattered, this causes problems for those who use and or collect aircraft clocks.  Every piece I service is recorded in my invoicing system and is tagged with my service label, as well as the mainspring barrel is marked in pen with the date and location of where the mainspring was last serviced.  Also, you the customer will have an invoice/receipt from Historic Timekeepers, Inc.

I cannot be responsible for someone else's work.





For shipping  or ordering information, contact:

Dewey Clark                   410.592.9998

Email Contact:         Historictimekeepers@gmail.com

Site Created and Expanded since 1999!!

(Watch my hair go grey)