Thanks guys. Tinsel, I have spoken with Faye, in great depth, from All Creatures (where our specialist referrals go) and also Marie Kubiak from here, but more briefly. Both agreed with each other.
It's 'only' teeth, but they are crippling him
I lose a lot of bunnies, but normally they come here and get more life than they would anywhere else. Now I'm facing losing one who was born here and that's not how it's supposed to be. THEY are supposed to live until old age, and they want to, he SO wants to. But I can't help him. My heart is being torn apart and obviously I have to do whatever is best for him, but when I make that decision, whilst it will still be 'easy', as always, it just feels like my feet are going to be pulled out from me. 8 bunnies here form solid foundations under my feet, and he is one of them.