As you have realised, sometimes a new set of eyes can see a different solution. "new behaviourist", "positive changes" - all good!

Just because Blue Cross says "No" doesn't mean that all will say "No".

If you go down the rescue route, you need to give them the full story. What about where you got him from? Would they take him back?

There are people who will take, and actively search out "problem" dogs - I know, because I'm one of them.