Rare? No, I don't think they qualify as rare but they are kinda scarce and don't come up for sale very often. Greg and Dale are correct, I do have two and they were made by Camillus. When they sell, they don't seem to go for a bunch of money, usually in the $20-$40 range from what I've observed but then I've not seen every one that's sold.
Apparently they also had them made for others as evidenced by this one for the "National Wood Carvers Association".
Edit: They had patterns other than the 72 made for them which may have been made by companies other than Camillus.
Forged on the anvil of discipline.
The Few. The Proud.
This country has become more about sub-groups than about it's unity as a nation.
"The #72 pattern has got to be pretty close to the perfect knife."
--T.J. Murphy 2012