Man. I thought he was older. He was big bodied cuss last year. I'll have to get better at aging. :-)
If you find a picture of him last year, post them. My guess is that it would change some of the guesses. Aging deer in the summer time can be difficult (I typically don't try to).
I would lean more to the middle aged if I was going to venture a guess.
Hope he sticks around. Good luck