From what I can tell, the lens barrel is made of aluminum alloy, and not anodized, so if the lens was stored forever it may go grey and require polish- thus the shellac?
I can't imagine they put the shellac on there as a finish, since it's not uniformly applied and the color is (was) inconsistent. A couple of paper towels with alcohol on them took it all off fast. I'm thinking the shellac was put on as a preservative, like the west would use that clear peel off plastic film such as comes on the displays of cell phones etc.
The lens did have to sit on a store shelf from 1953 to 2003 before being sold, and now looks gleaming and new, so I guess the plan worked!
Now I need a lens hood for the thing..
oh and to stop playing and take some photos!!
clint