Hopefully the bottom rib assy and stiffener are not corroded.
You have a bit of a sheet metal project on your hands, but it doesn't look complicated at all. The rudder has to come off, then remove lower rib, drill off damaged bellcrank, treat all alum surfaces, primer, then install. Looks like all rivets can be done with access to both sides, blind fasteners not req'd. One day job, if nothing goes wrong/no surprises.
We'll need to polish some of the bellcrank were it had been striking the rudder stops. (Damn student pilots)

We have access to a rivet squeezer and proper size rivets so, after everything is cleaned up, it should be pretty easy to assemble. I'll try to remember to take some pics. Can't say too many good things about Faeth aviation. Kenny Faeth is a good guy. This is the second part I have bought from him. The first was a fuel tank. Fair prices and he will guarantee his parts.