q for the OG's (about dealer pricing Back In The Day)...

q for the OG's...
Around when did the GreySheet become common for most dealers to use (I know it started in 1963 but around when did it become the (or at least one of the main) source for prices for even the Mom & Pop B&M place on the corner)?
And what did most mid and small tier dealers use for pricing before that? Was it really just Red Book/Blue Book?
Philately will get you nowhere....
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