If it was me... look at getting a saddler out to ensure the saddle is the best fit possible (perhaps use someone different to normal for another POV). Perhaps also physio/chiro. Have teeth been done recently?
Do loads and loads of desensitisation with the horse. Flapping stirrups, slapping...
all the ex-racers I’ve had have required a fortune spending on them in vets/dentists/physios to sort out problems they have picked up during racing. (Or in the case of the dentist clearly never bothered using one.)
hence why I wouldn’t been keen on spending much money on one, as they are likely...
What exactly has the vet checked for apart from ulcers?
I’d certainly carry out suggestions above, magnesium and watch some Warwick Schiller videos. Both low cost and easy to do.
depending on what the vet has looked at, it may be worth getting back/teeth/saddle checked by different...
Speak to them. I have always found SHB (GB) very helpful. With any luck the silhouette is on their database and it will just be a case of doing you up a new passport.
one thing to bear in mind though is the vaccination pages. I had to send my (EU) horses passport back for a new section ix. They...
Pretty sure in theory you can “force” them to sell you the horse under contract law.
however I’d suggest just get the deposit back and leave the hassle behind
Whilst I agree with the get off and lead past, you need to check with the owner if that’s a suitable option for this horse. I’ve certainly owned a horse that would just spin around and leg it if you tried to lead her past something she didn’t like.
you need to keep you and your horse safe... if...
Just a point, if original vendor refuses to release vet notes to you, the only way you can force them to do so is via a court order. Even then you may not get it.