Speed Demons gave me the idea of bending the plate to fit the battery (as he did). This seems like it would work; I could actually bend the entire plate into one flat piece and then mount it on the optional side terminals (see image 3).
However, I tried bending the plate (in one hand I had some vice grips, and the other hand I had pliers), but that plate seemed to be pretty rigid. I could try and give it more force, but I don't want to break the plate or anything...maybe a rubber mallet or hammer strike at the 90deg elbow of the plate would work??? Man...I hope I don't screw this up!