Well, isn't that something on the ringbone
Vet #2 has some issues, it seems
Great news, things continue to look up for this fella and for your intended purpose for him
Since you don't know this horse's history, hence its drug sensitivity, ask the vet to give the Rabies shot in the butt.
My 25+ fella has always been drug sensitive but he got worse once his metabolic issues exploded on him. He got his shot in the bum and still had a reaction; the vet stayed an extra thirty minutes to make sure he wouldn't go down.
He doesn't get any vaccines anymore, except rabies but my horses live on my property in "Deliverance Land" and don't go anywhere - lol
He had to have hooks filed on his teeth three weeks ago. The Happy Juice he needed wouldn't have phased two whiskers on a Mini. The vet did him first, then did the physicals on the other three so he could keep an eye on this horse as it seems he gets more drug sensitive as he gets older
Nowadays, there's an intra-nasal vaccine for strangles but I think I would still hesitate on giving strangles unless the vet really sees the need for it (if you've had a huge outbreak in your area).
As far as putting 1K into your horse - prices vary widely, just from area to area. My Chiro, (who is excellent and keeps two of my horses walking straight, including one with a fractured sacrum) would charge $125 to work on your horse and that includes a 45 mile road fee.
That being said, your horse would probably need at least two visits, a month apart, IF Vet #2 was anywhere near correct in his assessment
My vet would charge around $50 - $75 to do the teeth.
Even if the rates in your area are a lot higher, I still can't see $1,000 to get your guy feeling better
Here's to looking upward and onward and giving the grand Fella some the greatest last years that he no doubt deserves
Hugs to him