Hi Richard welcome to the Forum - you emailed me yesterday about a dash pad and instrument cluster for your "Firenza" - not as it makes any difference to the parts you are after but in the UK a 4 door saloon is a Viva or a Magnum depending on engine size and year.
A Firenza is the early HC 2 door coupe
- later versions were limited addition High Performance Firenza or Droopsnoot (like the Can Am in your country) followed by the Viva E coupe (small engine) and the Magnum Coupe
So your 4 door "Firenza" HC saloon could cause a bit of confusion over here
I see the pics show a twin dial dash which I could source for you - dash pads are more difficult a) to find and b) to courier to you.
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http://www.vauxhallviva.com/