Matthew,

I'm no expert, but do have one old ancient tree like this and have
transplanted about 95 11-15yo trees from an orchard that was closing down
and only had one DOA out of the bunch. A tree as old as yours is bound to
have some battle scars but I didn't see anything in the pictures that run
up
a caution flag. Overall it looks pretty healthy. As was mentioned in
another
post, I would take the time once it is dormant to open up the center
canopy
a bit. I spent a good bit of time on-line and talking with local experts
and
here is what I do.

snip

Any guesses as to the age of the tree? The trunk is about 36 inches in
diameter - big. I chopped down a tree half it's size that had about 70 or so
rings. I had to cut it down because one of the two main trunks had rotted
2/3 of the way through, and it was dangerous. Hated to do it, poor thing