The damage you describe hints of improper installation. I can't see it from here, so I can't be sure. There is a good chance that if you put new hardware on it, the same thing would happen again if they aren't installed correctly. I would guess that this hardware is not sold separately. I have only ever seen it as a whole unit. You can tell this because so much of it is riveted and not put together with bolts etc. It can be dangerous to monkey with these things as the springs are pretty powerful. I wouldn't even CONSIDER messing with this hardware. You should be able to pick up an entire new unit for $100 (or less) and install it in no time at all. You probably only have to remove the casing, remove the old unit, and replace with a new one and the same casing (if you get the exact same size unit. This should be 1/2 day job and you can do it yourself by following the instructions provided if you are at all handy.