Model 10-7 should be 1977 or later and have the standard (tapered) barrel. Specific dash numbers generally are produced for several years and may run currently with other dash numbers. This is why the SN is needed to give you a closer date. Value depends on finish and condition. It could vary from ca. $350 to twice that. To get any closer we need SN, and photos to judge condition from. uns made in that time frame were still typical S&W quality, so, yes, based only on time of production only it should be a good gun!
And, BTW, correct nomenclature. The "firing pin", in S&W nomenclature, is the hammer nose, not on the hammer nose!