There are a couple of references to Tony Weatherall and Neil Brooke's Whitchurch Hornpipe CD, earlier in this thread. Here is the Musical Traditions Magazine review I wrote. I strongly recommend the record, and the remarks I make in the review about Welsh fiddlers are, I hope, also relevant to the stuff about Welsh music earlier in the thread.
   There is a also a followup from the Snail to my earlier remarks about English fiddlers and rolls, trebles and decorations: he asked for chapter and verse on this in MS collections. I suggest a look at the copies of William Irwin's notebooks, which you can find at the Village Music Project website (I hope the decorations are reproduced, I have't actually checked). There are many other examples.This is not the place for a long discussion on the value of notebook evidence as a relibal guide to performance styles, but that is something you obviously have to consider with care.