Corroded gas tank locking tabs
 

So, my 2005 F150 Lariat was throwing a small EVAP leak code. I went through the usually procedures i.e check hoses, replace gas cap. I could not find any visible cracks in any of the lines. I then decided to pop the bed off so that I could take a look at the canister. Well, the canister turned out to be fine however the locking ring and tabs on the fuel tank were not. The ring was partially corroded but even worse, the locking rings from the fuel tank were either corroded or non existing. Now the question: do I need a new fuel tank? I know that I can replace the locking ring but I cannot find a part for the locking tab ring that seems to be part of the fuel tank. Has anyone had a similar problem? What are my options?