Okie
7 spacers on non leather handles ended in 1972. That should make your knife 1972 or earlier.
There were two part gray Combination Crystolon (sp) stones used starting in the mid 1950's until the late 60's.
The earliest were marked "Norton", then followed by blue, then white, then yellow markings. I can not remember the dates the marking/colors changed. But please remember dating a RMK by using a hone stone is one of the least accurate methods. The stones come out of bins, so first stone in can be that last stone out. Or someone could add a stone if the original is lost.