Larry looks less gaunt already. He doesn't seem buffaloed by Sam anymore and is drinking and eating better. He is a personable fellow, and was quite tidy in his space last night, using a small portion of his paddock for elimination and keeping his stall clean and dry.
This morning I got an old bridle that was my Swedish warmblood mare's fitted to Larry (he doesn't like flash attachments, and Russell's bridle has one), tacked him up with lunging surcingle and loose side reins, and took him out for a short lunging session. He is not as well trained on the lunge line as I'm used to, but I'm already seeing progress there, too. I took some photos of him at the walk; one of these days I'll have to get help to try and capture his trot for you; it is lovely.