Ive been in the market for a Model 60 myself bud, and to make maters worse the 60-10. I went with the .357mag rated 60-10, this way it was a bit more bulked up even though I was going to keep .38spl ammo in it.
Good luck in finding them, they are a bit on the rare side. Pre-lock model 60's are held onto.
each dash represents a barrel length, either 38spl or .357mag rated, and either fixed sights or target/adjustable.
My opinion is M60-10 has all the best to offer. .357mag rated, 3inch barrel, target sights. And as luck would have it I purchased it from a forum member. twomoons.
Good luck on the quest, just research and decide what are your parameters.