Howdy all: I have a BT-7, hence no roll-up windows, and the rim of the cockpit has the screw-on aluminum trim...rails? Whatever those are called. Two q's:
1) I very vaguely recall reading somewhere that these trim pieces should not be cleaned/polished. Something about the finish. Maybe I'm off base on that but I'm on the verge of doing a slight body restoration project and don't want to botch this. My plan was to use a non-abrasive auto metal cleaner followed by a polish like Happich Simichrome. Good idea or bad?

2) I can brute force the answer (ie test various screw sizes in bins), but does anyone know offhand the size of the chrome sheetmetal screws that hold these trim pieces to the door? I can figure it out by trial and error but if someone knows off the top that'd be great. Worth asking.

Many thanks,
-Tom

The trim should be a flatter anodized finish, not polished if you want it to be correct. Of course, you see many that are polished and almost look like chrome. It is hard to tell in the photo below, but I think you can see that the trim is not as bright as the chrome boot lid hinges or even the polished aluminum fuel filler cap. Typically, the trim is scratched requiring cleaning, polishing and reanodizing.

I forget the size of the screws but I will see if I can find it for you. The doors use self-tapping screws while the trim around the rear squab on the shroud uses machine screws.

Lin

FYI,
Mines an early BN1, tried buffing out the scratches etc prior to re anodizing, no good, kept hitting pockets of impurities in the original ali, ended up using a paint with a flat clear finish, looks close to original, and thats after a few years, being a later model you may have more luck

Stainless steel, beveled #8 10X32 screws about 1 inch with nuts and lockwashers were used. After removing the trim piece I lightly sanded and filled any crevices, then used a good metal primer. Then I used Eastwoods "Alumablast" paint following with a clear coat. Going on 5 years now and still looks good.
Good luck