I believe logic dictates that we have at least a partial answer to the problem. The high number series is from #657-787, which encompasses 131 cards. Add in the #604 checklist (because, unlike the earlier series, the high numbers only included one checklist) and that makes it the standard number of 132 different cards that Topps usually printed in a series at the time (two of each for a total of 264).
When I look at all of the images of uncut full and partial 1972 sheets I've collected over the years, one thing is perfectly clear. Like other years, each individual card is always located next to the same card on the print sheets. Therefore, each series checklist is next to the same cards in the two places it occupies on those sheets. So, if #604 (left side copyright) in next to #782, it will always be found next to #782. The (probable) conclusion is only the #604 (left side copyright) was printed with the high numbers. Of course, we can't actually verify that the backs of the cards had no differences, but it seems likely they did not. We still don't know whether or not the semi-high series had both checklist copyright versions.
Here are some of the images I've accumulated...
1972 Topps Uncut series1 Full Sheet.jpg
1972 Topps Uncut series2 Half Sheet.jpg
1972-Topps-Uncut-series5-Half-Sheet01.jpg1972-Topps-Uncut-series5-Half-Sheet02.jpg