He's cute - that's about all I can tell you from those pictures. You can tell he has just started his re-training as well.
Just make sure you are 100% honest with yourself when you go look at him. Do you have experience with re-training OTTBs? Some can be like riding an entirely different animal. I know you currently have a trainer & it sounds like you're going to continue lessons. Are you willing to send this horse to training if needed? He might be an easy re-train, he might be difficult. There could be a reason he's been sitting in a pasture since he was 6. Make sure you stay realistic about your goals. If you want to compete in upper level SJ - you don't want a conformation trainwreck or a horse with serious past injuries. Yes, there's underdog stories of some injuries rehabbing just fine. If he doesn't though? If he breaks down in a couple years?
Stay realistic. If this horse ends up not fitting into your goals & dreams - he doesn't fit. I can tell you from personal experience - I thought I was okay limiting myself for one of my horses. We'd never jump again, we'd barely ride, she was just casual pleasure type (mostly arena because she could be a bear on trails). I thought I was okay with that. Turns out after a couple months & a heart to heart with myself, I realized I wasn't okay with only pleasure/arena riding. So don't compromise :) Not saying he has any of these issues. You obviously won't know until you try him out.