For a tidy, easy fix, use plumber's ABS pipe cement.  ABS is what the
grill is made of, as are many other plastic parts on the van, and it
will create a strong chemical weld. No need to introduce other materials
or chemicals.  Best part is the cement is black, and so will also be
less noticeable than other solutions.  A dab'll do ya.

A good example of where else this works well; I used it to affix the
broken tabs on the rear emblems on my '88.  Good as new.  Also repaired
the tabs on the heater control surround, but for that I used clear
plumber's PVC cement.

Gregory Smith

Smith Design Studio
Small Building Company
Olympia, WA
360-239-0429
gregoryfsmith.com