I'm going the less authentic path, since I'm not ready to fully restore my truck. When I got my truck, the interior was spray painted primer gray with no stainless trim visible. Maybe my trim isn't stainless steel? So I had no idea of polishing trim. I was going to paint it.
There are a lot of discussions on interior paint color and after reading lots of them, I decided that I'd try the Rustoleum rattle can approach and see if I liked it. I think it looks pretty good and makes the interior livable, while I work on other things. Just for sake of visual interest, I used the flat version for the dash panel and the gloss/hammered version for the speaker cover/ashtray/glove box door areas. It makes a nice contrast. Since my truck is a 1953, the correct lettering color is white. Attached is a pic of the speaker cover with the trim piece laying on top. Since I'm not adding a radio, I used a piece of cardboard from a soda case, cut it to size and spray painted it flat black so that you can't see through the cover. I thought it did what I wanted it to do, once I installed it.
So I guess the take away is that it's your truck, do what you like. Polish the trim...or paint it. The stainless trim that I did polish (headlight trim and exterior windshield trim) polished up nice with a buffing wheel on the grinder and some very mild buffing compound.
