The following links I have found to interesting and/or useful.

From Kustom Fest 2001 at the Indianapolis Guitar Show.

General Links
Vintage Kustom Terrific site for Kustom freaks - classifieds, web-board, repair, restoration, and parts. Really wonderful people.
Vox Thomas Organ Solid State Amps Lots of info on keeping these odd balls going!
JK Lutherie Guitar and amp books and tapes. Also vintage parts. Jerry Hedge at the Cleves store is a terrific amp tech.
The Unofficial Sunn Site Sunn info, classifieds, and webboard.

Marshall 18 Watt Clone Site This is the site that got me hooked in the first place. The consumate homebuild site dedicated to the accurate recreation of the fabled Marshall 18 Watt Combo. Very informative site and wonderful people. Updated link to the new "18 watt portal"
The AX84 Project "The AX84 Project was originally started with these goals:
Design and build a simple tube guitar amp
Make information available and understandable to beginning DIY'ers
Discuss the designs and apply them to future projects
Promote an atmosphere of learning and camaraderie between folks who know and folks who want to know."

Schematic Connection Vintage and hard to find schematics - nice guy, too!
Mendlesons Surplus Super Store in Dayton, Ohio. Something else - spend a Saturday there.
Tube Glow Amplification High quality tube amps and DIY parts. Tell Tim the Komboking sent you!
Tatoo Amplification Cool hand built Marshall-esque amps.
Parts Express Good prices - interesting stock. Fun people!
Burris Engineering and the Tone Shop Incredibly nice guy - beautiful hand built amps - well respected repairs and mods. In lovely Lexington, KY.
Dr Tube Consumate tube amp and related links.