TSJ1975:
The small trigger guard increases the value by 50%, according to the Standard Catalog of S&W, if your friend is loking to sell it his best bet would be the S&W forum, to anyone else its a used chiefs special.
Robinett-11B:
The serial number on your Model 64-2 .38 Military & Police Stainless is 1D56737, not ID56737. It was made in 1979 or 1980, serial range for those years was 1D45001 to 1D99999, so 1979 seems probable.
MajorMajorMajorMajor:
Purists complain about the S&W guns from the 1970s (Bangor Punta ownership and poor quality control) from the 1980s (No pinned and recessed magnums) from the 1990s (MIM parts), and from the 2000s (More MIM parts, clear coat finishes, scandium frames, etc, etc). No one seems to complain about the guns from the 50s. They appear to be the high point of quality control in the S&W regular range, so old or not, its probably a quality gun. The grips are so valuable because many owners dumped the walnut grips for rubber in the 80s and 90s. Now collectors are trying to restore these old guns, so there is a market for the old grips with the diamond around the grip screws.