Steve,

 

I'm sure you used e-glass, since you need to see through the cured layup to draw the lines!  :-)

 

I use very similar technique and it works very well.  I added one other step.  I'm assuming exterior paint is finished.  I mask the interior side of the window with blue Fine Line tape, offsetting the tape edge into the window about 1/8" from the exterior paint line.  I lightly sand the interior surface of the window.  Then I spray paint that area with black.  Follow up with an additional couple coats with a color that matches your headliner material.  Then do your two bid window ring layups and mark them at the edge of your new interior paint lines.  When you trim the rings, trim them back about 1/4" from the pen line.  When you attach them to the window, and install the headliner, you'll have about 3/16" of your interior paint around the window showing.  On the exterior you have a 1/8" black line around the window edge.  By doing this, you don't see the bare fiberglass in the inside, and you don't see the headliner from the outside.  Whew!

 

Mike Easley

Colorado Springs