After looking at the dash pictures, I was wondering if the HX/HZ used a fascia plate around the AM Radio, similiar to that used in the LX Torana.
It was used to finish off the area around the radio slot after they had cut it out..



Apparently there is something listed in the HX and HZ catalogues as
Escutcheon Radio, Pt No:VS13164

If you're interested, I sell these here..
http://cgi.ebay.com.au/ws/eBayISAPI....e=STRK:MESE:IT

anyway, I thought it might interest some of you and I would be interested to know if it is the same...

cheers
Mick