Takedown & pivot pins can be delt with through powdercoat.
Simply have the coaters mask the body & detent groove portion and leave the flat of the small end and full head exposed.
They make a special heat proof tape for just exactly that purpose and would require no more effort than a single wrap around the pin(s) + a wee little 'tab' on the pivot pin masking to cover the flat side of the head where the detent groove ends.
The other bits could be PC'd too actually.
May require a bit of fitment upon assembly unless they too were masked, but would certainly end up more durable than any home applied coating or paint.
Well, unless you have a powdercoating rig at home, in which case its a moot point.