It is wonderful how a chance conversation can reveal an interesting connection. I remarked casually to a friend that I was cataloguing some title deeds from Eglwys-bach, Denbighshire. She replied that one of her acquaintances lived there, in a very ancient house called ‘Plas’, which contained a huge fireplace inscribed with the intials JW. She kindly sent me a link to some pictures from the website of the Royal Commission for Ancient Monuments in Wales.
Returning to the deeds which I had found in the Wynnstay collection, I discovered that Plas yn y Dyffryn, as it was called then, was the home of Ieuan Lloyd Jeffrey of Erethlyn and Margaret his wife in 1598. Part of the land was mortgaged to Sir Thomas Myddelton in 1606. There was a further mortgage by Moris Lloyd in 1664, when the property was referred to as Plas yn Erethlyn. Plas yn y Dyffryn and its lands, together with Tythyn y Werne and Ty yn y Llan, were sold eventually to Moris Wynn of Crogen for £578 in 1667. When Moris Wynn died in 1672, his lands were divided between other members of the family.
The estate in Eglwys-bach was acquired by none other than Sir John Wynn, hence the inscription on the fireplace:
Sr I[ohn] W[ynn], K[nigh]t & B[arone]t, 1684.
Hilary Peters

The Royal Commission is the investigation body and national archive for the historic environment of Wales. It has the lead role in ensuring that Wales’s archaeological, built and maritime heritage is authoritatively recorded, and seeks to promote the understanding and appreciation of this heritage nationally and internationally.
http://www.rcahmw.gov.uk/