Just about every vintage AR gets stripped and inspected. The Diana Giss systems (mod 60, 65, 66, 75) also have the seals replaced (I have a jig that makes disassembly/reassembly easy). Those with rust are reblued.
There are only 2 that I haven't opened as I know they've been repaired in Germany by a knowledgeable gunsmith.
The vintage ones with leather seals are always stripped (especially one other brand that starts with a 'W' and end with an 'r' as they are known for leather seal deterioration).
My logic is this; once I get them all fixed-up, they'll have another 50 year lifespan. I don't want to replace seals when I'm 97 years old

Chuck