other resources
 

Two classic resources on serialisation:

https://store.bluebookinc.com/Info/PDF/EGuitar/ElectricSerialization.pdf

https://store.bluebookinc.com/Info/PDF/AGuitar/ASerialization.pdf

other stuff

User reviews

http://www.harmony-central.com/User_Reviews/

http://www.ultimate-guitar.com/reviews/

American fretted instruments makers pre-civil war to WWII http://www.mugwumps.com/AmerInstMkr.html

Pictures through the years  http://www.myrareguitars.com/1960guitars.html

A1 Guitars Guitar resources http://www.a1guitar.com/

Vintage Guitar Info http://www.provide.net/~cfh/

Vintage guitars and forum http://www.vintageguitars.org.uk/index.php

All Experts These people know a thing or two about guitars: http://en.allexperts.com/q/Guitar-General-649/index.htm

Pro Music Find http://www.promusicfind.com/new/dating.shtml

Ducks Deluxe http://www.ducksdeluxe.com/datesvc.html

Fetish Guitars (Italian) http://www.fetishguitars.com/index.html

Guitar tips http://www.guitartips.addr.com/

Media Web Source http://mediawebsource.com/guitar/serial.htm

Vintage Rocker http://www.vintagerocker.com/serialnumbers.html

Guitar Directory http://www.guitardir.com/

Guitar nucleus http://www.guitarnucleus.com/serial.html

Guitar dater project  http://www.guitardaterproject.org/default.aspx

Lap Steel Guitars http://www.well.com/~wellvis/gitinfo.html

Gruhn newsletters (see #9 about fakes)  http://www.gruhn.com/newsletter.html

Vintaxe http://www.vintaxe.com/guitar_links.htm

Cheesy Guitars http://www.cheesyguitars.com/

Junk Guitars http://www.junkguitars.com/

Jackson Rare Guitars 1988 and 1998 catalog - shows how prices have increased http://www.jacksonsrareguitars.com/Historic-Catalogues-sp-3.html

Australian valve amps http://ozvalveamps.elands.com/

Stolen Guitar Registry  http://www.stolenguitarregistry.com/index.php

Guitar wiring diagrams http://www.guitarelectronics.com/category/wiringresources

Guitar nuts http://www.guitarnuts.com/contact.php

Classic Guitar http://www.geocities.com/classicguitars/guitar-links.html

General forums

Acoustic guitar forum http://69.41.173.82/forums/index.php

other instruments

Lute, Violin, Mandolin  http://www.daniellarson.com/

Mewzik http://mewzik.com/serial/ - all music instruments

wind - brass http://www.musictrader.com/serialnos.html

pianos - http://www.pianoworld.com/howold.htm

Morley pianos http://www.pianos.co.uk/info/pianos/m/morley.php

Yamaha Keyboard chronology http://www.yamaha.co.jp/manual/english/chron.php