Wayne,

nice tip re the skewer.

I make them slightly less than twice as long as the originals but not longer than the spigot they go over, the length is a guess. You should be able to feel the resistance when you put the tank together, that way the "grommet" doesn't have to be truly square to get a good seal.

I make them from standard sized silicone fuel tube, the size that fits all the 09 to 60 size motors I use. Damned if I know the size, I just call it standard fuel tube.

Luke