The Fire In the Hole newsletter had an article on it a while back also. I will try to look it up in a back issue and freep mail you with what they have. They had a number of letters from frogs of the fifties that traced it back. It all pretty much agreed with what I had been told in 67.
Stay well - Stay safe - Stay armed - Yorktown
At least that's how it was in the 80s on the east coast.