As promised please find underneath generic  information sources on
American Watches, Railroad Watches, Pocket Watches, 8-Day Watches &
Clocks, Military Watches & Clocks, Timers, : Please note that none of
the following
organisations can make  a direct  evaluation  of your time-piece

http://nawcc-ihc.org/ : Internet Horology Chapter 185 of the National
Association of Watch & Clocks Collectors: They conduct a never-ending
family-very-friendly on-line NAWCC Meeting.

http://nawcc-mb.infopop.cc/eve/ubb.x : NAWCC Forum. Please note that
their Chapter 149 is consecrated to early American Companies.

http://www.hoapress.com/ Email: sales@hoapress.com . Numerous
interesting publications available there.
Or, there is also a guide printed yearly: Complete Price Guide to
Watches by Cooksey Shugart, Tom Engle, Richard E. Gilbert, P.O. Box
3147 Cleveland TN 37320-3147 Tel. or FAX (423) 479 4813, (ISBN
1-57432-064-5).

http://www.AWCo.org/ Tom Mc. Intyre's interesting website. 

http://www.plads.com/m57/ : Ron Price's research work  on Waltham
Model 1857 and other interesting information

Serial Numbers:

Waltham Serial Numbers Search: 
http://www.waltham.ch , point  at "WALTHAM MEMORIAL" and click  at:
"Serial Numbers" or directly http://www.waltham.ch/cgi/waltham/search
enter your movement's serial number (digits) only. Upon clicking on
the subsequently obtained result you shall obtain  more data. Further
information are contained in our three  click-on "Abbreviations",
"Glossary" & "Manufacturing Years".

Elgin Watches Serial Numbers Search & Information:
http://elginwatches.org/databases/index.html look for serial numbers

Howard Watches Serial Numbers Search:
http://mywebpages.comcast.net/dchaplain/EH/E_Howard.htm

For other Brand's serial numbers, please consult NAWCC's forum.

Best regards
Claude Girardin
c.girardin@waltham.ch