Stu,
I did mine last year (March) and got 2 peices from my main dealer in Preston plus the connector pieces top and bottom. The part numbers are :-
moulding piece, 255853305, £16.20 +VAT
connectors, 171853339A, £2.36 + VAT
total price £21.81
I was told that I needed 2 pieces to fit around the front screen but the screen fitter got away with only 1. I have swapped the other one. The rear seal never had a chrome strip in it as standard but I have seen one fitted as a bit of extra bling.
Hope that helps, Dan