Jim:

I have a Syncro Westy that has a standard "awning rail"
pop riveted to the metal of the top just *under* the poptop.
That is, hidden under the poptop when it is closed, not below
it. Put there by the previous owner.  I assume he had some
sort of hand-roll-up awning that he stored inside and
then slid onto the rail after the top was popped.

By standard awning rail, I mean part #8 on this PDF:
http://tinyurl.com/2osu4g
I am assuming that is what you are talking about.  The
rail is pop riveted at an angle, as I recall--that is, not
perfectly parallel to the gutter, but lower in the back.
Maybe because of the poptop hinge(?)

I'd look, and take a photo, for you, but can't pop the
top one-armed.  But if you want me to pursue it, I'll get
someone to help me and get you a photo.

Richard
Boulder