First question and more important to me right now, what is the minimum grit required to start restoring a razor? My Father-In-Law gave me 2 diamond sharpeners at 260# and 380# (roughly cant remember exact atm but I know it is 2XX and 8XX) would these be atleast good to learn good technique on?

Second, is there a way to find out/figure out a grit on a stone that I have without knowing the grit? I bought one for $1 that has 2 sides and they both seem fine grits, but I know one is atleast a medium and fine..... both are smooth when rubbing fingers accross.... my F-I-L is going to dress and clean it up since the medium side is all chewed up and both sides are pretty grimy and dirty from being stored I guess. Atleast I know he knows what he is doing on that since he is a blade smith and deals with stones all the time!

Any help is appreciated!