I'm about to instal a 6 gallon wing tank, and was wondering if anyone had an idea of where I can get a filler cap from that'll fit. It's for a Mk3, and it's the standard Kitfox style of tank.

Is it a filler cap that's from a vehicle that needs modifying with the angled vent, or is there a dedicated part number? I don't think Kitfox stock them.

Many thanks.