Pocket Watch Database
"1089" 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.
From the American Horology Archive:
Hamilton Watch Co.
|Manufacturer Location:||Lancaster, Pennsylvania|
|Movement Serial Number:||1089|
|Estimated Production Year:||1894|
|Dial Feet Locations:||2.6, 18.0, 38.2|
1953 Hamilton Serial List
Help Us Help Others By Improving the Database:
Does this information describe your movement accurately?
Data Verification Reports
Mobilaero Top Contributor 243 · May 7, 2016
Serial Number 1089 was reported as accurate.