If it were my van I would have replaced the hitch. For my friend, I chose to replace only the rusted out arm, remove all the rust from the hitch and paint it. My reasons:
-When I cut the arm off, the tube was still about 5/32” thick (See picture).
-I tapped on every inch of the tube with my weld slag removal hammer and it was sound.
-He uses the trailer for very light loading; his walk behind commercial mower, edger, weed whacker and rakes.
-He is planning on replacing it after ~ one year.
I have to believe that others have faced decisions like this and I would value your input.