hi Briscoe, i have done what you said and removed the metal pipe from the turbo which goes to the resonator box and found a light green o-ring at the turbo end which seemed to be in good nick. as i looked at the other end that fits onto the resonator box i had only three quarters of a black o-ring (hensce air escape i assume). so the next question is where can i get these 2 o-rings from and is the green/black combo o-rings correct for this pipe. at the moment i made a rubber seal to replace the black broken one to keep the car on the road and to my surprise the whistle has gone away, so i am chuffed with myself but would prefer to get the proper ones fitted if i can find them, again thankyou very much for yor advice on this matter