Just to let everyone know who may have just joined this site in the past year, this was dealt with quite a bit over a year ago. Hank has been sending back secretarial sigs TTM for years. Save your stamps if you're thinking of sending.
I hate to burst everyone's bubble... but the Hank Aaron's are all clubhouse signatures/ghost signed. It was reported in a interview that he doesn't not sign TTM unless you pay his fee which I believe was $100 or so.