I remember some years ago, there was a link to a youtube video of a bloke rejuvenating graunched and scratched panniers and other ABS plastic items with a hot air gun. I think it was in Italian, but NOT sure, by any stretch. How do I go about finding it, if it is still available?

not panniers but same procedure.

https://www.youtube.com/watch?v=Q-dtbBzky-s

gr, Dick

The video says it all. I tried it on my KLR650. 2004 model with red plastics that turn pink in the sun. Yes it worked, its much better than before but the colour is a little blotchy. Maybe I needed more heat. I did manage to smooth out some scratches as well.

After I foolishly put a scratch in the black bumper of my wife's new car, I tried a hot air gun, as demonstrated in the video.  Big mistake.  The resultant discoloration turned a small scratch into a large, very noticeable gray blob. 
She was furious!   
I'm looking forward to the year when that episode is behind us.

As a motor trimmer, I've used a heatgun for moulded interior panel repairs for cars for years.  You really need to sneak up on the heat, it's very easy to overdo it.  A good adjustable heatgun helps too.

Al

A heavy hand...