Individual he thought it came from. There is a serial number on the case as well which is a 20 year Dueber which is badly worn. The serial number is 118080 and it is a pendent at 12 o'clock type. I don't know a lot about these things but in examining it, I wondered if the watch may have been in a different case at some time. Note that we're using the serial number from the watch movement, not from the watch case. Looking at the table of Waltham serial numbers (see example below), you can see that number 20,900,000 was made in 1917 and 21,800,000 was made in 1918 (marked in red in the table below).
To obtain watch parts correctly, it is important that Case numbers be used when ordering these parts. Different watch manufacturers place these numbers at different points on the case. This listing is a guide in obtaining the correct number.
ACCUTRON
BULOVA
CARAVELLE
WITTNAUER
Number inside of case back, embossed or stamped in black ink. Example N510 or 3170 or C852062 And dial# on dial at 6:00.
CITIZEN
Number on outside of case back; Older models usually begin with “4”. Example 4-063546 or 2030-915660.
Also Model is shown on older models Example No. BW-7244 or 71-2330
OMEGA
![Dueber watch case serial numbers Dueber watch case serial numbers](/uploads/1/1/8/5/118526369/920373368.jpg)
Number inside case back. Example: 145.012
LONGINES
Example:
Old watches (CMT2512-MO520)
New watches(L2.654.5)
Old watches (CMT2512-MO520)
New watches(L2.654.5)
PULSAR/LORUS
Number on outside of case back. Example Y432-5901
RADO
Number is on outside of case back And Dial # at 6:00
ROLEX
Number inside case back or between Case lugs at “12” position. Example 6334
SEIKO
Number on outside of case back. Usually 8 digits Example 6139-6005
TISSOT
Number inside of case back. Example 17422 or T281/381
Dueber Watch Serial Numbers
WYLER
Number on outside of case back. Example 722-946B
ZODIAC
Number on inside of case back. Example 722-946B
ZENITH
MOVADO
Number on outside of case back.