This is an interesting experience and I wonder if anyone has gone through a similar thing.
I bought my 71 Chally which had been completely changed to a red interior. I am changing it back to correct colors so, I am having to remove the paint, then leaving the original black plastic there if still in good shape or repainting again with black.
To remove paint off a plastic component is very tough. If you rub it, the plastic will loose its texture, and sometimes when painted, it is covered with so much paint that it looses its texture anyway, and gets a smooth finish which is not desireable.
My only hope was to use thinner very carefully as leaving thinner for a longer period will also melt the plastic.
After cleaning the plastic piece which sits at the lowest part of my dash (first picture), I saw that it was previously rubbed down, presumably to be painted red, and thus had lost its texture. So, in order to get the texture back, I would place a piece of tissue paper on the plastic, spray the tissue with thinner and wait 25 seconds then peal it off. It would leave the texture of the tissue on the plastic.
I have attached a sample of the proceedure showing half a plate being done so that you can see the difference between the two portions, and finally a portion of the plastic part which I completed (used to be red, first picture).
You have to be carefull not to leave it longer than 25 seconds because then the tissue will stick on and you are in deep trouble.
You can tell it is time to remove it as the tissue will change from a dark color (wet look) and start becoming more whitish in color as it is beginning to dry up. Thats when you remove it. Any way if you need to do this, try it first in a place not visible and verify your time accordingly.
Concluding from this, you find the right texture of tissue and you can put it on your plastic part. Voila!
Hope it helps some of you. Cheers.
