This is what I have so far ...
First picture shows a mystery hole right behind the quarter window trim ... is this a broken out stud? Same hole on both sides. Too small for a threaded clip, and don't recall any clip that screwed in from the outside.
Next pic ... I think I have these arranged correctly ... the spring clip seems to serve the function of lining up the trim front to back, the hook on the spring grabs a ledge on the trim to index it's position. ... I think
Third pic ... the end clip on the long back piece, found a few of these used originals in my parts, threaded on the back.
I could have sworn the original layout had the oval threaded clip in the rear position on the quarter. If the front mystery holes are broken out studs I have the replacement screw in studs I can use to hold one of the rectangular plastic clips.