Eisner did some of the artwork, but it was mostly produced by a staff of eight artists and writers, including 3 technical illustrators. Some of the artists over the years were Klaus Nordling, Dan Zolnerowich (of Sheena fame), Mike Ploog, Chuck Kramer, and Murphy Anderson. Anderson took over direction of the magazine after Eisner left in 1972.
Somewhere in my stuff I have a really nice cover that Eisner executed solo for an M-16 rifle manual. I actually used that publication when I learned to clean and assemble my weapon. When I find that cover, I'll post it. But in the meantime here are a few depictions of the lovely miss Connie Rodd: