Okay, here are a few photos of the SE-GI windows with impossible-to-find plastic screen clips on my 1999 Concourse. One screen is in place because I have enough clips to do ONE window. No cross ventilation for me until I figure out a way to keep the other screen in place.
First photo is the window with no screen in place. This shows the "fin/track" that the screen rides on. Click to enlarge.
Next we have an end-on photo showing a window with the screen in place, riding half on top of, and half in front of the interior side of the "fin/track" (and held on by my one remaining precious set of clips).
And another photo showing it from the inside, again with the screen in place.
Can only add three photos per post, so the next post will have a photo of one of the precious clips (takes 5-6 of them to hold the screen in properly).