From what I can gather polish exiles lived there till around the 50s,I had it pegged as being empty from later though (70s-80s)....shows what I know about it
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I heard something about a long legal dispute over it and that's why it got left to rot.
I don't suppose your friend mentioned anything about a tunnel(s) did he G?
Apparently there is a tunnel leading from this house to either the nearby church (St Hubert's) or towards the river Calder (though that may be just one of the lead mine tunnels).