Thanks for a wonderful article! My own Mamiya 16 Super restoration was far more basic: I did not polish the internal brass parts, nor did I attempt to build a flash sync connector.
What I notice when working on Japanese cameras of the early postwar era are signs of hand-crafting: A bent lever here (intentionally, as a factory adjustment), file marks there. I think of how different 1950s Japan must have been.
I don't mind restoring cameras like the Mamiya, because they are still fairly common, and while there's history in that old grease, it doesn't seem like a part of history that needs preserving, unless I thought I had a rare variation, like a pre-production prototype.
On the other hand, if I owned a Leica Luxus, so much of it's value is as a collectable object that I wouldn't touch it. At that level, buyers will very much want complete and original authenticity, even it no longer functions as a picture-taking device.