Quick-name the first year Topps sold complete boxed Baseball sets to collectors. Many readers probably think 1980's (1982 started a long run of these) when the question comes up but the first time they did this was 1974, when Sears and (I believe) JC Penney offered them in their stores and catalogs.
Behold this magnificent beast, courtesy of Friend o'the Archive Brian Marcy (of Scottsdale Baseball Cards) :
These are hard to find these days but happily even though the above is example is devoid of any cards, a recent eBay auction filled in the missing bits:
I'm not sure what kind of pattern these should display if unmolested (like the zebra pattern in Topps vending boxes) but there ya go. Another Friend o'the Archive - Brian Yossef - advises the "Washington NL" variations are not present but that the red team checklists found their way into these, as did the Traded cards.
The bottom reveals the commodity code:
The 02 revision number is interesting but doesn't always mean the first version was retailed.
Some more views here, looks like a mouse got to some of the box:
Sears price stickers can be found on sometimes on one of the flaps, not sure about JC Penney versions, if they indeed sold these. These are not easy to find these days, hard to believe they are 45 years old! Now, compare the above to the regular 1974 wax box graphics:
The basic background is the same. We get a bottom view too:
That's a 1-302-70-01-4 commodity code if you are keeping score at home. Not a match to the full set's at all. Side view, check, just not quite as tall:
The other long side is, of course, not something the full set graphics could have shown:
I mark this as the true starting point of the modern era cards. Once the various series got the boot, it was off to a pretty generic look for most of the decade thereafter. When Topps had no direct competition in a market, that's how they blandly rolled.