Gary,
I bought my gas tank at Carlisle from Van’s Auto - give them a call, they should have what you need. In addition to the tank, you’ll want the replaceable rubber grommet that sits in the well where the gas filler pipe goes - they have these as well (it may come with it).
Assuming your fuel level sending unit in the tank is OK, you’ll want this tool to remove and put back in - I’m happy to lend to you: Faulkner gets a Redo - #637 by Faulkner
Because the replacement gas tank holds a bit more gas, and is a bit larger than your original tank, you’ll need longer “J bolts” for the straps - you can read about it here: Faulkner gets a Redo - #639 by Faulkner
Here’s a blurb where I’ve got my tank back in: Faulkner gets a Redo - #659 by Faulkner
You’ll also want to make sure (or, your mechanic) that when the float on the sender is perched in the tank, it is close to the bottom so it properly indicates “Empty”. It’s not a bad thing if it tells you you’re near empty, when you’re not; the converse would be bad! But you can bend the float rod a bit if need be. You can spot where the float is, by peering through the inlet for the gas line. I found that I didn’t need to bend mine.
Good luck! Report back. Keep safe, keep healthy.
Dan