I didn’t see if anyone asked about turn out for the old man? Let him get out and play on his own. Might take some time to teach him to relax and not go crazy outside. He’s used to LOTS of work and needs to learn to chill but you also need to remember to breath and release it out down your spine and seat to let him know to relax!! Any place to trail ride with calm quite horses along side of him to get him to enjoy and not want to run off on you? Don’t go out alone till your comfortable but always let someone know where your going. if you can, its getting harder as the urban sprawl takes more open spaces for riding. Glad your riding him. I have worked studs that had been hurt and stall bound except to bred and they can get nasty and mean. So he just will take time and the baby dressage will keep his mind active and not stress the older body. Enjoy him but build up some upper body strength so he doesn’t learn to get away from you.