Body-sore is actually quite common for racehorses. The gelding is a prime candidate for that because he appears to have been overworked for his condition. He looks like an old-style racehorse, and with proper feed and care, he could be a looker. I'd be concerned about wear and tear to his legs too, depending how long he's been on the track. If he is body-sore, it could take several months for that to subside- gentle flat work with a lot of slow gentle lateral flexion and working him slowly into a collected form. Slow, slow, slow, and probably bute and glucosamine for anti-inflammatory properties. Ice or cold water on his legs too. He just looks like a horse in pain and under track stress that has not been cared for. Take care of him well, and he will adore you.