My problem is the collar that determines how long the telescoping arm is. The screw that tightens the collar won’t budge. I broke off the thumb-grip on one screw trying to turn it. All hinges are fine.
I have to admit I've not seen with my own eyes this type of thing regarding shutters, but just now did search and find a 'clam shell awning' that had struts on either side -->here and here. Is what's in the photos there what you are contending with? Those are more sunshades than storm shutters, near as I can tell...
A bit more searching led to a small image of a adjustment 'slip collar with screw' --->here among the small images under label "Awning components".
So I think I see what you may be contending with.
How much plywood ya' got? {8^')
Eh, but maybe you won;t be needing any, anyhow.