Blackjack,
1. Sell the others and keep the one you love to DRIVE. They still make the others, but not any more Excaliburs.
2. That said, if mental instability takes a firm hold and you give him a price, the six I've seen sell in the last six months or so have been in the $33-$40 K range. In my opinion, yours is in the top part of that range. The last one that I know of, xxx177 VIN, was sold by Harry Kaufmann (dealer in vintage cars) and my guess is that it went for over $40 K with 16 K miles. Nice car with a late (probably the last) regular VIN. Your car is comparable in condition and some of its features are very rare (built 4AODE, awsome hardtop, sorted exhaust, 9 inch, BLACK). Call Harry and see what he thinks they are worth and where they are going. I read in Kit Car the new Excalibur effort is not happening, more reason to prize your Excalibur.
3. Take some deep breaths, sell one of your garage queens that you don't drive often and keep the black beauty- seriously!
Mike