I just installed a new fuel tank (Canadian manufactured via eBay) on my '60 Bug Eye. Every thing was going fine, including the dreaded fuel line fitting, until I tried to put the cap on the filler tube. The filler tube inner opening is 37mm and the center part of the cap (with the ears) is 38mm. I'm thinking about using an exhaust pipe expander to widen the opening to accept the cap but am open to suggestions. Thanks in advance. I've been lurking and have already benefited greatly from this group!