I can add another name to the list of people who have recorded William Irwin tunes. Pete Cooper has a new book and CD out called "English FiddleMusic"(published Schott World Music). It includes "Iron legs", a hornpipe form Irwin's notebooks. I can strongly recommend this book, excellently researched, 99 interesting tunes. And backed up by very extensive notes to the tunes, and biographies of traditional fiddlers, on Pete Cooper's website. The notes were too long for the publishers to print them in the book, alas, but having them available on the internet seems a very good alternative.