Yes, it looks home made. That said, pushing the brake pedal is going to lift the first bar, pulling the second and the brake with it. For that setup, it looks correct. Correct, but not very efficient. It appears the brake pad shows just how inefficient it really is. I think I would get a new brake, place what is now the lower mount on the stationary bolt. Then reconfigure you link(s) to pull down on the mobile mount. Think of it this way. You want the braking motion to go in the same direction of the drum. The whole thing would probably work better with cable, than fixed length pieces of steel.