Ken613,
The '62 has a rosewood riser with gray glass and pointed limb tips. The 64-67 were curved stripes and can be identified by the serial number. First digit 5-65, 6-66, 7-67. Any other number a 64. I have three 66 Magnums and none of the grips fit my hand well so I don't know if it was a change made that year or just the way the final shaping was done on the ones I have. The 64s, 65s and 67 I have owned were all a better fit.