I never did get a reply from Rimmer Bros so decided to get a set of 'genuine' QH ball joints.
Cheapest I found was from this place....
http://www.wilcodirect.co.uk/
I've stripped down one side of the front suspension and the copper shim I fitted is in perfect condition and the taper had not come loose after ~3000 miles.
I have the same problem with the new QH ball joints where the lower joints taper is travelling to far inside the BMW strut hole.
(see picture in post #20 above)
I have not checked the upper joints yet..........