if it is a receiver type hitch it would be easy to make a lock down clamp nut that would tighten against the receiver, otherwise making a angle iron bracket to triangulate the fuel cell mount to eliminate any play would be a fairly simple thing to do, don't scrap the whole thing, it should be able to be modified to work...
"you don't quit riding because you get old,"
"you get old because you quit riding"
Brett-IBA#326/TS#515