I was in the area back in June (Jun 18th) and also spent a great deal of time looking around and in this tree.
I even tried checking under the tree's sign post for the coin. The label only had a fraction of the 'Benjamin Fig' text remaining, as was the case with the other posts in the park. The post was somewhat rotten and broke off leaving some remaining in the ground when I tried to free it from it's resting place.
I spent about 45 minutes up and around the tree. Found a few deep V's that were clogged with leaves, dirt, and bugs. I dug as far as my fingers could reach between the V of the branches then had to dig at it with my multi-tool. Still couldn't reach the bottom though. I did not climb any more than the initial trunk either.
I have a few other leads on this but not much.
Feel free to have a collective leap to anywhere this might take you:
The final boat of the
Benjamin Franklin class ballistic missile submarines
USS Will Rogers (SSBN-659) was named in his honor.
http://en.wikipedia.org/wiki/USS_Will_Rogers_%28SSBN-659%29#Deactivation.2C_decommissioning.2C_and_disposalBeverly Hills Mt. Wilson aka (
Benjamin Davis “Don Benito” Wilson (1811-1878)) of Beverly Hills
https://drive.google.com/file/d/0B9n9O9tSlHYWWWVwT1hGYUdPYm8/view?usp=sharingBenjamin's grave is a short drive from the park.
http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=4620