I'm trying to identify the age and value a 38 special. It's stamped model K and 15.2 with a serial number K634XXX. it's got a stock wood grip with a diamond shape around the grip screw and a 6 inch barrel. It's also has another number I can't tell what it is, the number is 442XX with the letter Z and 3 stamped in the same area. Any idea of the age of this gun and approximate value?