I just got this very nice and (I think) untouched for at least 100 years old 1881 vintage KWKS watch which is in the cleaning process now, and this is the case "as received". It weighs just under three ounces!

Is the reference to "Aluminum" that is stamped into both covers for real?

In the 1800's before modern aluminum refining methods were invented, aluminum was regarded as a semi-precious metal.

I would regard "ALUMINUM SILVER" on a par with "ORE SILVER" or "ALASKA SILVER" when stamped on a case. Just another trade name for base metal.

Ed, I must agree with you, and only can say that this has a more "grey" cast. The Brasso (I usually use for Silveroids) did nothing for it. So I used the stuff I use on my Harley's un-plated Aluminum cases called "Aluminum Doctor" which gave me this! . . . Oh, btw, the movement that came in it and still lives in it seems to be a NOS 1881 Hampden 15J "Woolworth" which when I was finished cleaning looked "factory new"!