To save that air cleaner housing, I would soak it in a liquid rust remover to get all of the rust out. Then use fiber glass cloth and fiberglass resin to patch the rusted through spots. The patches will show so put them on the inside. If you have not done this before there are how to video’s on you tube. Then use a good grade of body filler over the outside surface where the patches and the pitted surfaces are to bring them back to smooth. You will be putting on a thin layer so get a filler intended for final smoothing. A lot of effort but doable. Or continue the search for a better air cleaner housing.
