Well, sometimes you get lucky! Yesterday I emailed the vet practice that now occupies Park Issa. In this morning's email there was a wonderful reply from Karen, who works there - she sent me a copy of a brief history of the building itself, which was compiled by a previous senior partner in the practice who was evidently interested in its history. Karen said the sketch on the home page is of the building. The first mention of the house (according to the history) is in 1771 on a map showing the intended road from the Black Gate to the Turnpike Gate on the way to Shrewsbury. Most of the history is to do with architectural changes to the building, but it also includes who was living there at various times. It was occupied by the Kyffin family from the late 1790s, and by Thomas Kyffin 1833-45. Back to the 1841 census and on the first page of District 17, which covers Salop Road, is Thomas Kyffin, 75, so that dwelling, second on the page, has to be Park Issa! There is a Charlot [sic] Williams of about the right age who I am tempted to think may be our Catherine, but that needs following up. The most interesting thing is that several branches of Catherine's family are littered with men who have the second name Kyffin. It even extends to my husband's grandfather, who was born in Australia in 1880. I reckon there's a connection here... Ian, thanks for your hints about the properties and their evolution - did I mention that the old maps site has a Parc-Isaf on a map of Oswestry dated about 1888, in the same location as Park Issa (the vet)? I'm told Parc-Isaf and Park Issa mean the same thing. Your theory about Park Hall in Whittington sounds good - I think I will follow it up through the censuses and see if I can find out when it became Park Issa. Maybe that will solve the problem of which Park Issa Catherine was living at when she wrote her Will. Thanks, everyone, for your help and interest. Cheers, Loretta