I hit the headbadge on my 303R a few time with a dead blow hammer. Not a hard hit but some taps to seat the rivet back it. I did that a few times and I haven't had any more problems.
A shim in the back would work for awhile but it will just come out slowly again. The rivets don't penetrate enough to keep it tight unfortunately.
A shim in the back would work for awhile but it will just come out slowly again. The rivets don't penetrate enough to keep it tight unfortunately.