Hey, the more I search, the cheaper this fix gets !
http://www.ebay.com/itm/Filler-Tube-...3D122300052435
This is the only brand I've found. It's FitzAll #K35999R. Don't know if anybody else sells the end.
But obviously, you can buy the hat seal most anywhere. They're about $3. Probably even cheaper, if you buy local, where you don't have to pay shipping.
http://www.ebay.com/itm/TransTec-700...ZS6aM3&vxp=mtr
https://www.summitracing.com/parts/ado-1259475
http://www.jegs.com/i/ACDelco/065/1259475/10002/-1
http://www.rockauto.com/en/parts/acd...ick+seal,10970
How about $.79 ?
http://www.oreillyauto.com/site/c/se...zer&vi=1050714