Aah- I didn't realise they operate that way. I wasn't expecting that, so thanks for telling me. There's nothing matching our needs at our nearest Blue Cross centre, and I have checked the other branches as well. Nothing doing.
We have more or less decided not to go for a puppy at his time. There are plenty of adults around needing to be rehomed for whatever reason, so it's a case of waiting for the right adult to turn up. We didn't expect it would be this difficult, or take this long, but I suppose we do have specific requirements for it to stand a chance of being a successful adoption.
Thank you for your interest and helpful info , Bazaar1.

There are plenty of adults or young adults looking for a home that I'd trust with kids, I know of three or four at our center that would spring to mind instantly, depending on what you wanted. I'm sure the other branches are the same, well worth a chat over the phone with your local breach.