Anyone replaced their Turkish Tempest piston seal with a John Knibbs one? The photo on their price list of parts shows a rounded shape as opposed to the square faced ones in my guns. I've been in touch via email and been assured that it does have a split in it for fitting (cant see one on photo) but they don't know if it works in the Turkish version! They say its the English made replacement and SHOULD work. I wondered if it might be made for the Brummie Tempest. Is there a difference? Chambers don't have them in stock. ATB. Pete.