I used a coat of etch primer followed by two coats of high build primer, lots of elbow grease to smooth the high build primer then five or six coats of cellulose. Another big helping of elbow grease to wet'n'dry the topcoat then Farecla G3 cutting compound and a final polish.
The cellulose came from Jawel as a complete kit -
http://www.ebay.co.uk/itm/Cellulose-...item4176daeeac
they recommended using etch primer first so that was extra, but I managed to do the whole job for about £400 including the compressor and a couple of spray guns.