Good for you & him! He's a very lucky boy.... now! Sounds like all is going well. If he's gained some concavity in such a short time, I'd say they may not have been quite as bad as they looked. I wouldn't want to try to force the issue though, without at least knowing exactly where the internal structures are. Further concavity tends to just come when the feet start to become really healthy. Did you get xrays? Mightn't be a bad idea, especially considering it sounded like long term neglect, so you know if/where any bone remodelling has happened to know how you may have to trim differently.
He's probably thinking- OMGosh pain free walking yay!!
Maybe he just bucked you off because he can do it without sore feet!
Sorry to hear you fell- recover well and well done for doing so well with clyde!!
Great! I'd be interested to see some sole shots too. One of the links in my signature takes you to a page explaining best angles for hoof pics. Yes, he has got quite short looking feet for his size. Did you get any xrays done? Be interested to see those if you did.