White letter Hairstreak, thanks Neil, Even Better!!
Thanks to Neil Hagley's eagle eyes my Purple HS is in fact a White Letter Hairstreak. He saw my photos and was able to put me right.
I had presumed that it would be a Purple HS as I have seen them locally. Lesson learnt, look more closely and presume nothing! My excuse is that it was heavily worn, but you can see the row of orange crescents on the edge of the hind wing.
This lower image does show the remains of the W on the hind wing. Interestingly there is some Sucker Elm on the Rough. Best of all it is a Butterfly tick for Paula and takes her to 51 Species. Great to get a new species in the back garden!