In the process of restoring my 750, i picked up a gas tank coating kit from a company called Caswell Coatings. It's a two part epoxy that you mix, swirl around in the tank, and drain (you must remove the tank, petcock, fuel level thingy, and plug all holes of course). Not to sound like a commercial, but it will save you a ton instead of replacing a tank. The kit cost me a about 35 bucks..and no, I have no affiliation with the company, but wanted to pass this along to hopefully save others a few bucks and the headaches of dealing with a rusty tank...

http://www.caswellplating.com/

Looks like a nice product.
HERE (http://www.caswellplating.com/aids/epoxygas.htm) is a link directly to the epoxy page.

And if 1 pint will do 2, 5 gallon tanks, it would probably be able to do a Vulcan tank 3 times.

I'm going to try it out this weekend, so I'll try to post a review after the deed is done...

TDHallum, hope that went as expected. You are still gona report back aren't you? I'm curious how that went.