KJA, Sir-Doris,
Many thanks for getting back to me ...... The 2 parts are off the vehicle at the moment - Muffler removed by me and the tailpipe is probably still in a road side ditch near Manchester Airport....
As mentioned in my hastily amended after reading your various ones, post, its a December 98, petrol model and with most of the ebay and internet exhaust dealers I've tried so far, the parts they bring up seem to be for the Long Wheel base version....... but I will still try which ever links you can point me in....
I do have in addition to the part numbers provided by Vauxhall a diagram of the system that I can fax or post copies of if of any help in identifying the correct parts ??