I bought a set of gakets a couple of years ago. A few months after I put
them in,I had to remove one box for some reason. The gasket had been
crushed flat in this short time. Without pressure against the steel and
plastic box,it will not seal well.

I believe that a gasket sealer will fix this.Silicone is my choice.I used
it for over a year and it seals fine. Needs to be smeared on the box and
steel.

Another issue is the 5/8 inch screw that attaches the boxes. Like lug
nuts,these need to be tightened in stages. Doing one all at once ,then
going to the other creats stress in the  plastic edges of the boxes.The new
gaskets are significantly thicker than the groove in the boxes,where they
fit.The new gaskets need to be compressed in stages described above. The
edges of the utility boxes crack, or show stress marks at a later date, if
you install them wrong.

I think a gasket selected for UV and ozone resistance is best,but dont know
if they exist........ Sounds like a job for...........Ebay Vanagon parts
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