Well, after I say this I know that I am going to sound like a broken record, but it's not my fault that this works so well!!!!
I sprayed some paint on a practic model and got the 'orange peel' effect, similar to the 'dusting' that you are talking about. I used a series of sandpaper that I got from HobbyTown USA, a national hobby store. It starts at 3200 grit and goes all the way up to 12000 grit, I got a MIRROR finish when I was done, and that was starting with a bad paint job!!!!!
I really recommend this method as opposed to Future Floor Polish because of the polish you can get. I saw an add in one of the 'Fine Scale Modelers' I have for a set of the stuff for around 8 bucks as opposed to the $17 I paid at HobbyTown and intend to get that next time. If that is the way you decide to go, let me know and I will try to find the website for the cheaper company and get it to you. No sense in two people getting ripped off!
Matt