Thanks for the replies...
I suspected the fault lay with the plater as I've had many brass parts stripped in the past without problems (by this plater in fact) but wasn't happy with his explanation of the situation when I raised the matter wth him...These parts are too difficult to find to have them f****d up by an incompetent plater so I guess I may having to resort to posting them off to someone else if he isn't admitting to a problem...Ian