Bwahaha, thanks for the laugh Perry...brat
Dubie,
Yes, you're correct on the first part...
As to the second part, you may want to differentiate between introduction and use dates, following the premise that when a new feature or characteristic was introduced it would subsequently supersede the previous feature or characteristic, with caveats...
Generally speaking, the 'Separate S' blade stamping method first used in mid 1967 was superseded with the 'Integral S' blade stamping method in mid 1972...but, as a caveat, during the high inflation and interest rate period of the late 1970's (you're old enough to remember those days), RMK, in lieu of purchasing as much new (high priced) steel as they may have in the past, IMO, instead dug a little deeper into the blade bins, utilizing a large number of older blade forgings in the process...
As an example; we purchased a 60+ RMK knife collection a few years back in which the majority of the knives were ordered and received between 1978 & 1980...at least five of those knives, possibly six, utilized older 'Separate S' blades. The 'Low S' blades introduced in early 1964 were used primarily through 1967, but we’ve seen 'deep bin' blades of this type used on knives that were built and sold well into the early to mid 1970's...
Anyhoo, I've got a trail to the lake to finish, hope that helped...