Used to get mine at Lowthers in Brierfield near Burnley but hes just closed down! One of the lads that used to work there has set up and called himself Pendle Motorcycles. Just had a rear Diablo fitted for £100 all in which I didnt think too bad. I think he would do a ride in ride out service but you would need to speak with him. It may be too far you though?
http://www.pendlemotorcycles.co.uk/home.htm