Thank you for your replies.

The house is registered, well, I assume it is, I have a copy of the registration from the Land Registry

Although the house is just over 60 years old, my parents bought it new, so no other transactions

As far as I know, Dad never paid ground rent.

I can remember moving in on Christmas Eve 1954.  All my brother and myself were worried about was if Santa knew we had moved.

I have left all the faffing about to my brother, which he is happy to do, and I am happy to let him get on with it.

Thats what brothers are for.

The Estate Agent told brother that buyer is a first time buyer with guaranteed mortgage funds, whatever that means.