I have 3 TR-3s. I am working on a 60 (produced in 59). Gas tank filler was the type with a nut inside the body. I have a new (Moss) that does not have the nut. If I use the style without the big nut inside what holds it in place? If I use the style with the big nut (which I am leaning towards since that is what the car had) does it get a rubber washer/gasket between the filler cap and the body? Does it also get a gasket between the nut and the inside of the body panel? I took it apart years ago, took great noted except apparently on this piece. My daughter got sick and this has lingered for a few years but I am back at it. Appreciate any insight. Tom