There's a huge discrepancy in panel fit on most cars from the 70's, but vans, being a commercial suffered from the "near enough is good enough" attitude more than most.

Some vans have tailgates that have considerable gaps and need extra rubber, while others (like jaft), need thin rubbers to get the tailgate to shut!

Each situation needs an individual solution it seems. I'm lucky mine is in the middle somewhere but we'll see what happens after I paint it and fit new rubbers.......