Posted By:
Jon CanfieldTed, while I can't answer your question from first hand knowledge (I also met Larry a few times as I grew up a mere 20 miles from Cooperstown), I believe we can deduce that Larry was NOT aware of the Russell collection from what we know of Larry's finding of the Doyle.
First, we know (or it is believed) that Larry discovered and acquired his first Doyle while looking through a collection he acquired. Since we know Larry acquired his first Doyle through this collection, we know that he was not merely looking through the Russell collection since the Russell collection still has its Doyle (and that Doyle was not acquired by Larry).
Secondly, we know (or it is rumored) that Larry believed his Doyle was unique after being unable to acquire another through his advertising. That is, until, the Huggins auction. So, since Larry thought his Doyle was unique, it would lend credence to the fact Larry did not know of the Russell collection (or at least the existence of a Doyle in there) since had he known of Russell's Doyle, we would have known it was not unique.