Thanks to all for the suggestions.
I sucked out all of the old gas through the gauge opening with an inline pump. There was a heavy layer of gelatin left over. I used my pressure washer with a solution of Simple Green to break up the goo. I pulled out the slurry with the pump and then used rags to sop up the residue. I tied a cord on the rags and used a stick to move the rag around. It is spotless clean now. I inspected with a bore scope and the tank looks new inside.
Now on to the wiring and other minor details and I will be on the water!
Can't wait to see how these famed V20's perform.

BassOMaticII