All I can say is good f/luck! Without them, you're sol, if you're the kind of guy who likes it done right.
I don't know what insert/clip/retainer it was. (I think that it was a dash retainer, and other assorted parts, for the RWD Deville, Fleetwood--the full size--ones in the late 80's early 90's. Was the chebby the Caprice/Impala, the Pontiac, the Parisian (sp? you know me) I don't know what all of them were called. I only knew the cars as W905's, and I didn't need to know all the minor details.
Anyway, my solution was to take those clips, gently clamp them in a vice, and with a utility knife and lots of elbow grease, trimmed them to fit. When I installed them, they split. However, I was able to torque the screws well.
As my eplaination as to what clips I used, I have sfb and failed to think about the because I should have kifted a few. I'ts my best guess that if I take the dash back out, I'll need new clips.
Here's something else you may try. I don't know if it would work, but it's worth a try. Take an approiate sized speed clip and try to align it behind the metal structure. Use a big wad of dum-dum--strip caulk, the clay type stuff--to hold the speed clip in place. That might allow the slop you need to get all the screws aligned.
