Pocket Watch Database
https://pocketwatchdatabase.com/search/result/e.-howard-watch-co.-keystone/4539
Access Date: March 12, 2025
"4539" could possibly indicate the grade of the watch and not the serial number of your movement. Serial numbers are usually more than a few digits.
Due to the lack of existing factory records, our E. Howard Watch Co. (Keystone) database has been reconstructed using observations of known watches.
As a result, the information may contain inaccuracies. Please let us know if you have details that can improve the database.
From the American Horology Archive:
E. Howard Watch Co. (Keystone)
Grade: Missing Data
| Manufacturer: | E. Howard Watch Co. (Keystone) |  |
| Manufacturer Location: | Waltham, Massachusetts | |
| Movement Serial Number: | 4539 | |
| Grade: | Missing Data | |
| Model: | 1921 | |
| Estimated Production Year: | 1921 | |
| Run Quantity: | 1,000 | |
| Grade/Model Run: | 1 of 1 | |
| Grade/Model Total Production: | 1,000 | |
| Size: | 10s | |
| Movement Configuration: | Openface | |
| Movement Finish: | Nickel | |
| Movement Setting: | Pendant | |
| Plate: | Bridge Plate | |
| Hairspring: | Breguet | |
| Case: | Various | |
| Run ID: | 5.G1.10S4.101921M4.O5.P5.J1 | |
| Database Version: | v52.622 | |
Production Metrics Tree: Grade Missing Data
Target Profile: 10S-M1921-J-ONP-U
| E. Howard Watch Co. (Keystone) Grade Missing Data (All Variations): 89,490 ETP | |
| 10S: 1,000 1.12% 10s, Grade Missing Data |
Other: 88,490
Other Sizes or Unclassified |
| 10S-M1921: 1,000 1.12% 10s, Grade Missing Data, Model 1921 |
|
| 10S-M1921-J: 1,000 1.12% 10s, Grade Missing Data, Model 1921, Jewels |
|
| 10S-M1921-J-ONP: 1,000 1.12% 10s, Grade Missing Data, Model 1921, Jewels, Openface/Pendant/Nickel |
|
| 10S-M1921-J-ONP-U: 1,000 1.12% | |
Help Us Help Others By Improving the Database:
Does this information describe your movement accurately?
Verification Reports for this Run
The following reports have been graciously submitted by dedicated members in reference to this production run. These reports are useful to verify data and track inaccuracies that require further research. Please note that reports may contain inaccurate information or assumptions that must be dilligently considered with other available sources.
Anonymous · July 31, 2022
Serial Number 4790 was reported as accurate.
Anonymous · April 25, 2022
Serial Number 4858 was reported as accurate.
kenpar16 1 · January 3, 2020
Serial Number 4812 was reported as inaccurate.