I just got done adding the passenger side light to our 82 Westy without
using the metal plate.  I just made sure that the hole I cut was just the
right size to hold the lighting fixture.  Since I don't plan to be pulling
it out and putting it in too often I considered this to be a viable option.
And yes, it certainly helps light up the interior much better than the stock
set-up.

Good Luck!
Mark Sheflo
82 Westy