The grips look like an original early PP. The SN ???? None of the PP's had a "T" suffix that I know about here. How did you arrive at the date for the PP? Sometimes the number on the crane is not the SN. Check the gun for more numbers. Remove the grips and look at the numbers on them. They should be listed as the last three SN#'s of the gun. Please describe the barrel stampings in full.
Most police positives are at the bottom of the barrel for value, but some people believe the better examples are "sleepers" that will eventually come into their own as all Colt firearms increase in value.