Glad the 414 got through. just been looking at Haynes and it is not very clear on the derv disks, would hate to give you the wrong size.
Hope someone will come along who knows the size.
Hope its a simple fix on the turbo, doesnt sound a bad price for a rebuild.
just found these on ebay, gives front disk size
http://cgi.ebay.co.uk/ROVER-MG-ZS-TD...item4150981b4b
and rear
http://cgi.ebay.co.uk/ROVER-MG-ZR-ZS...item27ac34f7ff
but best to measure yours or ring and give your reg No. I,ve got a feeling I had 2 sets delivered before I got the right fronts and the rears were done at Nationwide.