im not sure of the part number. but they sometimes come up on ebay. and if your keen there are proper chrome ones that came out on the older commo's they look mint.
thanks any way guys, i found one in my draw at work, i'll just take it to spare parts
( and i don't want chrome ones because i've got matte black ceptor's, chrome wheel nuts and then i'll paint the center caps matte black as well :thumbsup