The tank in my J15 was custom designed by me to give more leg room in the passenger side of the car. In addition to the custom design a large aircraft style filler was considered desirable to minimise any spillage during filling. At the time of originally writing this I was under the impression I needed a lead free valve for the purposes of the IVA. If you read the comments it became obvious that this fine fabrication was not needed. However I never completely disposed of it and poat IVA I found a use for it. See "Fuel system modifications" 13th Dec 2013.