I am not an authority on this subject, but I do not think they are scarce at all. I found two model 10-6's this past weekend at my fav. gun shop and bought one - 10-6 with 4" bull barrel in nickel.
I'll post pix as soon as I pick it up.
I'm hpoing that they get in a .357 of some interesting sort to replace the model 19 that I so foolishly sold when I was an ignorant 20-something.
As a general rule, Nickle Guns are more common before WW1 and Blue Steel Guns are more common thereafter.
That being said, and in the face of insufficient info that would help identify your revolver, Nickle Plated model 10's from the 60's to now are not rare, but indeed less frequently encountered than Blue.