Isaac Hill map is discovered

It was three weeks ago when my son brought the telephone to me. “Someone wants to know about the Isaac Hill map,” he said, as I reached for the phone.
The caller identified himself as Mike Deschais of Lansing, Calif., and he asked what I knew about the Isaac Hill map.  Well, as it happens, I know a lot. 
I began to tell him of the two maps and accompanying ledgers, and of Jack Cole, in whose custody they had been.
Following Jack’s death in the early 1970s, the maps disappeared. I first saw the maps in 1986.