IMG_4608
Left is original 45M2721. Right is replacement 45M2724. Obviously these are not the same. Turns out the 45M2721 is replaced with 45M2723 and 45M2722 is replaced with 45M2724.
I read on a forum "If you plan on replacing the fan yourself besure to get FRU # 45M2724 and not the same FRU as your defective fan (Most likely 45M2722)". That's what I get for trusting forum posters. I just broke off the extra metal plate though and it fits fine.