Carl,
Thanks for the advise.  I'll take it and paint over the primer with a close
matched color for now.  I probably will not attempt to paint the whole van
myself though.  I really only have a few panels that need work.  I may tackle
that in the spring using your methods.
Thanks!

Eric,
Good advise as well.  I did notice some very old silicone on the windshield
frame, not just in the corners but all the way around.  I assumed it was the
DPO's attempt to fix the leak without replacing the seal but perhaps not.  I
was told that professional windshield replacement shops use a butyl rubber
based product for this.  What do you think?
Thanks for your interest.

Mark,
I recognize that Bondo may not be the best product for permanent rust repairs.
I took a chance and went ahead and used it in this location because the hole
was small, the seal completely covers the repair completely and the repair is
not subjected to rain water or road splash from the inside.  Risky perhaps but
I will keep a close eye on it.  I grew up in Maine and the smell of Bondo
always reminds me of High School shop class.  The rust buckets we could afford
to own always needed more work to get the required twice a year state
inspection sticker!!