The JSA and The Avengers in "Cruel Intentions in Dual Dimensions!"

I featured a these two teams together in their more modern incarnations a few weeks back, and I thought I would try my hand at a more retro cover.  I used to love checking out the All-Star Comics reprints that would show up in 100-Page JLA issues.  As cool as it was for me to see all those heroes together at once, I can only imagine how it must have felt for a young fan seeing the original issues on the newsstand back in the 40's.