Not sure if this is worth anything to anyone but I'm replacing the ebay gti badges with OEM ones and my local trade parts place gave me the following info
Front grille GTI badge with red I
part number - 6N0853679F KTP
description - inscription 'GTI' chrome/red/black £19.42
Rear boot badge with red I
part number - 6N0853675D GQF
description - inscription 'GTI' chrome/red/black £21.88
Decal / Badge Part numbers and prices
Re: Decal / Badge Part numbers and prices
just for what it is worth, these are no longer available according to TPS as they cannot fulfil my order