Tom I found my reciept I bought the battery in Feb. 04.The stock # was g24fa/hdr. I paid $230.00 for it. They also have the original lead acid type for much less $.
Cobra Make, Engine: Building 289 Lemans / FFR mkIV chassis w/ Bruce Chervenak
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Tom, National Parts Depot make have what you are looking for.
Here is a link to their online catalog page with the battery shown. Not sure if it's exactly what you are looking for but this is from their '65-'73 Mustang catalog.