I've used all of the 3 Novus Polish Products. They are good.
Keep in mind the bottle size will have an impact of just how far you can go with them.
Novus #1 is essentially not much of a polish product that is then designed to remove fine scratches, it is more of a maintenance and final use product that is effective to remove dirts, dusts, fingerprints and leave a nice shine and feel behind.
There are also a number of other products marketed for specific use on Plastics, which are no doubt preferable than using polishes and compounds designed for use on painted surfaces. Meguiars is one, and there's a number of others.
Today, there are also various products sold that are designed for Plastic Headlight Lens Restoration. These too can be another option and can be also used and work well.
In regards to what you call an eccentric buffer, I'll assume you're referring to a D/A Dual Action Random Orbital Polisher.
Such can be gotten from many places, Harbor Freight, and so many others.
Most have the standardized 5/16" Thread Attachment for Backing Plates and Pads. While most are designed for use with 5" and 6" Backing Plates, a number of them can be teamed with smaller 3" (2-7/8") Backing Plates, and respective 3" Pads of choice. This will make smaller jobs like Dustcovers an easier task.
Any given polish can be further fine tuned with what Polishing Pad is used with it. There are different types of aggressive Pads some softer for finer finishing polishes, and some coarser for use with more aggressive Polishes and Compounds.
They are commonly either Foam, or Microfiber, the Microfiber generally being more aggressive in cutting ability.
By only changing the type of Pad with any given Polish, the degree of cut can be modified-changed, just like with auto finishes.
The biggest enemy of plastics will of course be heat. Or the improper use of polish products. That's where a D/A will hold advantage versus a machine such as a Rotary Polisher.
Places to buy the needed Pads, Plates and even the Polishes of various types would-could be a online store such as Autogeek or Autopia, their sister site. As for such, they'll carry about the largest, most diverse selection.
Polishing Plastics of course goes further than the products I mention above. In that wet sanding Papers might also be required. Consider that the coarser the Papers, the harder it will be to remove the scratches instilled by them.
To use the least aggressive methods and products to get desired results.
And yes, this can mean Wet Sanding Papers in 1000, 1200, 1500, 2000, 3000, 5000 grit. Use something as seemingly fine as 400, you very well might instill more severe damage than any buffing methods and products can remove.
Hope my comments have helped.
