Jason:
Your boat has the same hull design as mine:
http://www.wellcraftv20.com/gallery/...umName=album06
It looks like you found a nice solid hull with a good engine. I don't know if you'll be able to reach tuna territory, but I added a lot of range by installing a third fuel tank under the bench seat that I installed in the stern. It holds about 18 gallons. My boat's prior owner also liked to fish offshore. In order to get additional range he secured two portable 12-gallon tanks on either side of the engine in the engine well, which you can see in some of the photos on page three.
I really like the in-floor hatches of the V-20 models that were produced in those years. When I'm fishing I fill my rear hatch with saltwater and use it to hold any fish I catch. Even after a full day in the sun, the fish are generally still alive when I return to the dock.
A number of guys on this site will likely advise you to replace those teak hatch covers with starboard in order to reduce your maintenance. If you're inclined to do so, please don't throw the old ones out. I may be interested in buying them from you.
I hope your boat gives you as much pleasure as mine has given me. Good luck.
Fitz