Dirty harry used two model 29-2 the one in the scenes was a 6.5 barrel and promotional pics and movie posters. Was a 8 3/8. Your gun is a four inch barrel 29-2 with target model cocabola grips.The solid checkering on the grips indicate it is a N serial number gun, The s series had a diamond in the center.
The pictures look like it is in very good condition and worth around 900 dollars. With the box paper work and tools 1000 dollars.With a mahogany case and liners in good shape with tools 1050.