I don't have one for sale, and they're quite rare. Since some of the most seasoned Henry J owners do not know what they looked like, I'll post this picture of one. I've seen a number of Henry Js on ebay that claim "original jack..." but they don't. The original jack, looks like this and it's pictured in the 1953-54 owner's manual and the shop manual.
and here's a pic from the HJ Owner's Manual
Was the one used by the Darrin the same?
I got this one a few years ago. I see Sunstar models got it right in their Henry J models which is pretty cool.