What are some of the more difficult sets from the 70's?

[toppcat]

Here's the Trader Speaks for October 1971 with relevant content on Greatest Moments, followed at the bottom by a single page from the June 1973 issue with the first CCC ad I could find that mentions the set. There's some bonus content on 1971 Topps regular series distribution and a few other goodies but the east coast vs west coast theory of how these sets came to the hobby is interesting to me as is the "no short prints" dealers. It would be a little of both to my mind-test a set you think would do well and when it doesn't sell, dump it through CCC Haber and the like.

The "53 Reprint", which is really a Goudey homage using artwork already issued in '53, is still the subject of scrutiny and there are various ways it could have been handed out initially but it follows the same rough trajectory as Greatest Moments. At 8 cards, it's likely too small a set to have been a retail test but a lab or field (schoolyard) test is possible to me. Most if not all Topps sets, regular or otherwise, could also have seen at least partial distribution in Fun Packs or similar repackages as the used different avenues to shed overstock. And in the June 1973 ad, were those the Boxed Batter Up sets of 1968 Game Cards?