Nice work, nice old rola out and about.
Not sure if this is what you mean, i have polished a fair few plastic headlight lenses, they come out like new. Same process as polishing wheels really. Sand with course paper 120 grit dry if they are bad enough to need it, or finer if they not too bad. Then work down to 800 wet. Then use buffing compound for 2 pack paint and a sander/buffer with foam pad for paint, coarse compound then fine grit, they come out like new.