A84.2QuattroSport

I am going nuts trying to find a supplier where I can get the center caps for my 1996 A8 4.2, 18inch 5 spoke alloys, center cap hole measures approx 65mm outter lip and 55 inner lip, I think the guy who had the car before me glued caps in so they are a mess but I have completly stripped, painted,etc one wheel and thats the hole size!!!.....anybody help with a part number or a solution??

Kind regards,
Jon