To test if it has a clear coat:
1) Wash the spot you will perform this test on.
2) With fine wet and dry (say 1500 or 2000) wet sand a small patch.
3) Check the colour of the water under the paper.
If the water has started to turn the colour of your paint, say black in your case there is no clear coat. If the water started to go a milky colour you probably have a clear coat.
Either way have a go at JohnS advice, you may surprise yourself.
Be very careful of the edges when sanding or machine polishing - best not to sand and only hand polish the edges to start with.
Few ideas for polishing.
- Wash and check no dirt etc before polish.
- If using wet and dry it may pay to use a soft pad behind the paper - better than leaving pressure marks where your fingers are.
- Do it in the shade with panels as cool as possible (drive down to Vic!

)
- If you have a few compounds and pads for your machine, start with the least aggressive.... you can always escalate if it is not doing it for you!
- Your VG is black if I remember, be patient it will be likely to show swirl marks so you will need to finish with a good polish. Have a look at the Meguiar's products, they used to indicate how aggressive they are with a numbering system 10 being the most aggressive.
- don't use too much polish
- don't polish dry - dont let the compound dry out as you are polishing. this can cause bad swirl marks. You can spray a little mist of water on with a hand pump bottle.
- don't polish with extremely high rotational speed (can cause too much friction)
Being an Oz classic it was probably painted in acrylic. Does the paint mark with your fingernail leaving a very slight dulling on the surface (faint scratch)?
Reason I ask is the paint may be quite soft even though it is years old (this is the case with my Monaro painted about 17 years ago) used to polish ok but am running out of paint to polish.
Good luck

We all know black is the worst colour to keep looking good on close inspection.
Hope to see some before & after shots if you are happy with the results.