Interior and exterior trim differences

[C15_Sierra]

This past weekend I pulled all the pillar trim and exterior cab band from what I think was an '87 Sierra Classic..or so says the dash and emissions sticker, as the doors were not the originals and no fender emblems.

Anyway, I pulled the trim thinking I can use it on my '80 GMC project. I looked up on LMC and it looks like all but the A-pillar trim will work - whats the difference there? They don't list a '73-80 pillar trim, did those trucks not come with A-pillar trim? Will the '87 work in mine? My truck is just a plain Sierra so I'm gonna be drilling into the cab anyway...all the screws I pulled were sheetmetal screws so I assume thats how it was done in the factory.

Regarding the exterior trim, again going by LMC, the exterior cab band looks to be different '81-'87...again what gives? Can I install the '87 cab band on the '80? Truck doesn't have cab molding clips so if I were to install the '87 band, I would buy the clips for an '87.

I know it will not necessarily be period-correct, but to the untrained eye, is it gonna matter? There are other parts of the truck that aren't "period correct" I would just like to know if it will look totally out of place