JimWood: Are you taking the serial number off the butt of the gun? The numbers you have there don't appear to match anything in SCSW. The SN should be either 1 to 5 numerical digits, or an "L" followed by 1 to 4 digits. If the "1203" you mention is in fact the SN, then it would indeed be an earlier version, likely shortly after the model introduction in 1952. Value depends on condition, but in general Model 40s appear to command higher prices than similar revolvers, with one in excellent condition being worth several hundred dollars.