I would try a little bit of rainmaker, esp around the upper hoof into the hair even and massage it in well. if hes going to be shod soon try and not paint over the nails as much, if you over do it he could get too soft and rip his shoes off more easy. I agree with you going slow on the food too till you know what hes ok eating, who knows what those yahoos fed him.
I'm almost certain it was only pasture. He's got bot fly eggs all over his legs as well as whelps on his body from them. So, it's safe to say he's had very little conditioning. Poor boy...
Ropo, in the midst of your happy reunion with Max, please be careful of possible retaliation from the family who had him. I'm thinking of someone harming or stealing (again!) the horse. Keep his location a secret, and keep him indoors at night or in a pasture with camera surveillance (but that won't stop the bad guys).
I'm not trying to throw cold water on these happy times, but I am one of those people who try to think of everything that COULD happen, so that I can be prepared. My hubby said that 95 percent of the stuff I worried about never happened, but I said, maybe not, but I am PREPARED for the other five percent.
I am sure you want to just be over and done with the loosers, but ya know, at this point, I would be tempted to sue the jerks for the condition you got him back in, medical care etc.. you have to put into a horse that when he was leased was perfectly healthy!