Pretty high chance of it being a Premier if it has a hammer.
Grips...chances are you'll have to either make something else fit...or carve some yourself. The upside...you can use almost any solid substance to make 'em...deer horn...
Numrich does have grips listed, but few pics...
Harrington & Richardson*|*G-H REVOLVER GRIPS*|*e-GunParts.com
This set has a listing for Premier models...I'd hazard a guess that yours is a Small Frame Premier.
http://www.e-gunparts.com/DisplayAd....SKU=267470&MC=
As mentioned above, without pics, it's just a guess.