But i now face more problems with another dog we have rescued! but i shall post a new thread on this one and it will shock you all.
Oh boy, you have us all awaiting that one.

Very, very, pleased at the outcome with Buster, you have to just give him the chance, he may well be in capable hands able to control the situation, (or not) but there is no way anyone should ever try to change the mindset of a powerful breed with children on the premesis, it takes time and effort and even then may still not work, children can not be there as potential victims. You have absolutely done the right thing.
I know your vet is involved, but if Buster can not be helped, I think it best for the owners there to take him to their vet to be pts, I know it would break my heart to have to collect him and take him myself. It is up to you, but I know it would really upset me, especially as you have thrown him a potential life line, to then be the one to take it back, would be very hard, for me at least.
Thank you for the update, I know many of us will be very happy, I have my fingers crossed for Buster too, let us know how everything goes there. There is always hope.