I just got a set of these blank ones on eBay. $80 for set of 4 +postage

http://www.ebay.com.au/itm/Holden-HQ...item2ebc2fadc0

Added some decals from Grafix Unlimited $10 each decal.
http://grafixunlimited.com.au/holden...hq_hj_hx_hz/hz

Decals are good and close to the originals.

All in all, a cost effective solution for your rims I would think.