I was very pleased with the credits on the last page myself.

VisualFiction, the problem with those ADVENTURE covers is that most were wraparound covers. In fact, of the 6 issues that featured the JSA, only the last one (#466) is not a wraparound. All of the wraparound covers highlight every feature in the issue, so the JSA story gets at least a mention on every cover. But it would take 11 pages, not just 6, to include all of them, and you'd have to have 5 double-page spreads in the back for them. I miss them too, but they're not as important to me as the ALL-STAR covers, and I can see why they would be omitted.

Oh, and the page counts for most of those JSA stories are rather healthy. Remember, they were originally intended for a comic that would have had 25 story pages due to the short-lived "DC Explosion". So, you have :

#461 - 13 pp (plus 3 pp included in Vol. 1)
#462 - 13 pp (splash was intended cover for ALL-STAR #75)
#463 - 17 pp
#464 - 8 pp (originally intended as backup for A-S #76?)
#465 - 16 pp
#466 - 17 pp

I sort of wish the JSA could have stuck around in ADVENTURE, but alas, the "Dollar Comic" experiment was already dying even in 1979.
"Power corrupts but superpower corrupts way better."; - Scott Adams, DILBERT AND THE WAY OF THE WEASEL