The 24 was first produced in .357 Mag in 1979, and that was also the last year of the 'half moon' receiver. That year had the fatter squared off pistol grip cap without the savage medallion. So if your receiver has the 'half moon' cutouts where it is mated to the stock, it's a 'first year' .357 Mag, and shouldn't(to my knowledge), have the medallion.
In 1980, they went to the straight sided receiver(where it meets the stock), and the smaller grip cap with the Savage medallion. The 357 Mag was only made till about 1982 or 83, when the 357 MAX made it's debut, and then the 357 MAX was only produced for a year or 2, including for one year, in a VERY RARE model called the 24VS, which was a nickle plated gun with 20 inch barrels instead of 24 inch, hardwood furniture, and an additional hardwood pistol grip.
