Forum member Daisy kindly responded to my wanted add with info of a listing in her local paper, and what a cracker it is. It's a BX 17 TZD that's been very well looked after and although it has been to the moon and back and is suffering from some lacquer peel i reckon it'll make the perfect loveable workhorse. The vender was the perfect gent, it has to be said.
Et voila:

And he she is back home with the other members of my fleet:

The journey homeward went well and I've only got a couple of niggles- A clicky speedo will need to be looked at and I need to source some suitable wheel trims and front speaker grills. All in all, I'm very happy indeed.