In the end, I was able to send pictures of the tank and filler neck fit issues to LMC. I had told them that I would prefer an exchange if they had an item that would fit properly. They had R&D review before confirming that they did NOT have the correct item and issuing refund.
I attempted to have my original tank cleaned and resealed. The tank was not holding up too well after the power washing.
Thank you for suggesting the Spectra tank! I see that the Spectra Premium fuel tank (#GM55A) is available at Rock Auto ($151+$16 S&H), O'Reilly ($259), and Advance Auto ($249).
I purchased from RA. I will post an update after it arrives to compare to original tank and confirm fit in my 1952 Chevrolet 3600.
