Hi David,
Many thanks for your swift and positive reply.
No, I am not related to the family, but I had (have?) family members spread across several valleys, due to the Industrial Revolution. Bare in mind this is an envelope only, no letter included. I live in an ex Victorian Post Office, and have several items that were franked here by the Postmistress over a hundred years ago, and it is satisfying when items return 'home'. I will place a bid, and let you know in a week how we get on!
Regards
Graham.