Thanks for the replies guys.
From the Rimmers catalogue the parts are described as the windscreen trim finisher in 2 parts left and right .
He has got the rubber onto the screen and then fitted to the car , so this is where the problem starts ,looks as though the trim should have been fitted to the rubber before the screen put on the car? I will advise him on this ,thanks very much for the advice , will let you know how he gets on .