The guns used in Dirty Harry were Model 29-2s made in S&Ws tool room as the model was not in production at the time the guns were needed. I don't know the serial numbers. The gun used in Magnum Force is a 4-screw with a serial number in the S206000 range. The photo below is me with the Model 29 at the Southwest Bunch gather in Tulsa in 2011.

Bill