The issue of restoring is always an interesting one. When a friend and I reworked two Fecker Celestar 6 Maksutovs recently, we opted to do a 21st century renovation of the instruments rather than a mid-20th century restortion. That meant doing everything in the spirit of the original (e.g., no digital setting circles, Telrads,radical changes).
Paint was obviously a major problem, as the Feckers used a speckle finish that was difficult to match. So we did our best with what was available.
Our goal was to restore two unusable instruments to top performance without compromising the original design, not to put something in a museum display.
Every restoration project will have to approached differently and on its own merits. This was just what we did.