Wear, if excessive will show up with front-to-back looseness when grasping the two ends with the bracket held in a vise or still in place on the center cross member. The original bushings are sort of a fabric material and best replaced with impregnated bronze or nylon. I know of no one who offers the service, but any competent machinist should be able to do it. The biggest part of the job is getting it apart starting with drilling out the rivets holding the arms on to the ends of the shafts (unless you are lucky and it is a early '33 with easy-to-remove tapered drive pins like '32 instead of rivets.)