The economiser valve on my carb is leaking and will need to be replaced. So far no luck getting the correct part out of the rebuild kits I've purchased. INFO; 1965 Autolite 4100, 4 bbl. C5ZF-C C5EA, 4 speed and auto choke. Should be Tune Up Kit C4OZ 9A586-A and all I really need is the Economiser Assembly Kit C4OZ 9A565-A. Anyone have a source ? Thanks, Brian