Jack Reed's notes on the subject (last month) are excellent.  Unfortunately,
his information on the likelihood of rust in the trough on the top of the tank
is also right on:  that's where my leak is -- a pinhole in a field of rust
about 6 in. in diameter.

I took Jack's recommendation to run the car low on gas perhaps too seriously.
The car had less than a quart of gas in it when I drained the tank.  Now I
have to track down a used tank, or see if some brave soul welds gas tanks.

The only change I made in Jack's steps was to use a transmission jack under
the tank.  Not because the empty tank is heavy -- it's not -- but because the
jack lets you drop the tank a little, look around, find the connections you
missed, get a flashlight in there a little, without the worry of a gas tank
in your lap.

The trough that catches dirt and rusts is for the hot air duct, so if you
smell gas when your tank is more than half full and the heat is on, you may
have some seepage and be on the way to my actual leak.  Just another old-
Vanagon nightmare for you to lie awake about.  Not a problem if you keep the
tank low, but the gas station guy was wondering why I was in every day for 
$3 of premium.

Jack, thanks again for the notes that confirmed it's a DIY job.
B.