I wouldn't over think it. Just try the coarsest foam pad you have with the compound. If it's transfer, you'll see it start to come off. If not, You'll know it's abraded and you need to move on to glass polish.I haven't tried any polish/compound. I was reading in other threads that they wouldn't do anything, but perhaps that was because the scratches were much deeper?
I have some DG105/205. Should I just jump straight to the DG105? What pad should I use with it? Or try by hand first?