I wonder if the fact that he's not keen to jump could be related to his feet hurting... His breeding suggests he should be good at jumping... (sire- Cavalier Royale dam sire- Sea Crest). What do you think?
I cannot help with the feet, I am not knowledgeable in any way there, and there is nothing I could tell you about them anyway, you know your stuff!
However I can tell you a bit about his breeding. On breeding alone, he WILL jump. Practice is a different matter though!
Cavalier Royale is a Cor De Bryere (sp?) Horse out of a mare called Ligustra (sp?). He was a continental horse, Holstein I think, and an absolute legend of ISH breeding. He crossed extremely well with Irish mares, and he appears in an awful lot of top class ISH eventing/SJ pedigrees. (Look at Mary King's Imperial Master, He is by him, there are many many many examples.) His back breeding has a lot of TB in it, Rantzau, Cottage Son, Ladykiller etc. Basically all the founding fathers of the modern WB competition horse (most of these were Irish TB's too-no wonder he crosses so sell, and those WB lines continue to cross well with Irish mares). His successful progeny are too many to list, and there are numerous stallion sons around, approved and not approved!
Cavalier Royale's sire, Cor de la Bryere, is one of the most influential Selle francais sport horse sires, he stood in germany and went back to France. He appears an awful lot in modern sporthorses too, and was a legend in his own lifetime.
Sea Crest was a beautifully bred Irish draught, who is the sire of Ireland's most successful modern SJ stallion, Cruising. Cruising jumped internationally (won the Aachen Grand Prix)and has 1000+ offspring reg'd. Interestingly, you say your horse has small feet. Cruising was known for getting neat little feet. Sea Crest was by a mare by Tara, the damsire of Clover Hill, who requires no introduction! His sire Knockboy was also a graded jumper, and an athletic ID. Sea Crest was a Grade A jumper also. Sea Crest is also the sire of Lenamore, Caroline Powells 4* campaigner.
He is long dead now, so I am guessing your horse is either really old

or by a horse by Sea Crest, such as Coolcronan Wood?
Cavalier Royale died in a fight with another stallion when the other stallion got in to his field. that stallion interestingly was French Bred, and has gotten some seriously classy eventers.
The man who stood Cavalier Royale was one of the of not the earliest adopter of continental bloodlines into Ireland. Cavalier Royale was not approved in the ISH studbook for years, as there was considerable suspicion around him being foreign bred, and was only fully approved in later years. It was his incredible progeny performance that in the end got him fully approved. He was the first foreign bred to have an influence in Ireland. He has also been dead for sometime now, so most of his stock are older. However, there are still straws around off him so there are a select few youngsters still around by him.
Very nice breeding, ISH royalty actually! Are you aiming to jump/hunt him?
ETA if you have his reg'd name, or dam's name, I can give you his comp record from when he was over here (Assuming he did not leave as a foal)