When I am rebuilding telescopic sights, where required I only ever use modern seals, lubricants. If I have parts remanufactured I don't even hesitate to do so - using modern materials too! And I would never, ever stake the turret screws over either!
Off the subject a tad but as Armourers, we would stake screws, bolts or nuts to keep them secure. Indeed, that's the very reason, say, band screws are countersunk. (Don't believe me....., just look...) So we could secure them with a light centre punch. I bet that nobody would be so foolhardy now!