David’s solution is easier than mine! Why didn’t I think of that?
My guess is if you don’t have immediate access to a welder, you could also drill a small hole through both tubes (where they overlap) and secure them with a small machine screw…..
Rocky
PS. The other thing I noticed was that the fit of the body/bumper was improved by judicious grinding on the bumper inner edge as needed.
The bumper was never really shaped to be that close to the body…