Some NET54ers who helped me in this quest were Bob Craik, Scott Brockelman and Joe Gonsowski. Thanks, guys! The Doyle was the first, as I said, picked up at an Oregon Trail auction. Most came from major auctions but 3-4 came from ebay. A couple came from the 2006 National.
Tom, I have seen the Michael Reeve info you cited. Great stuff. I do have a couple of non-baseball subjects but I'm not planning to go any further into N566-Land. As you mentioned, there are variations within the series in cropping, titles etched onto the negatives versus not, mount differences, etc. But nothing really significant to the degree of a T205 Hoblitzell no stats. Thank God!
Joe P., now I'm onto the N172 Brown's Champions. I'm about half way there.