i Think this is just the Model 13 Power Pad...if you look at the Top Section you notice it looks just like the Top on the Regular Model 13.....its Definetly Not a 313 or a 315 Powerpad.
I belive it was called the 13 Power Pad and later renamed the 313 poerpad (right before the 113 came allong.) Would love to see one of these with a drop lens
I have seen these with a drop lens, they have some with drop lens in Colorado Springs. And In kentucky in elizabethtown. You can find these tons of places.