I am sorry if this has been asked before, but I was looking at Lara's pictures of St. Mary's church where Katherine Parr was entombed. And as I am looking I realize that the stained glass windows are copies of known portraits of Edward, Henry and Elizabeth. There is a stained glass window of Jane Grey, and of Katherine Parr of course. So now to the question, when were the windows put in, did they take copies of known (at the time) portraits of Jane Grey, and Katherine Parr, and could that help to identify unknown pictures of Jane Grey and Katherine Parr? Especially ones there are confusion about?
[Ed. note - here is a link to the photos: http://tudorhistory.org/places/sudeley/gallery.html