www.925-1000.com

Aha..I'm reading "wiesse Alpakka-Unterlage" (aka Neusilber) as "white Alpakka-underlay/base". This would seem to imply the the use of "Alpaca" in the government charts must be the un-plated WMF version of white Nickel Silver (something slightly more specific than generic white metal).

Do we have any reference from WMF that actually defines "Alpaca" as their "base metal"?

Yes, but they're more likely to call it Neusilber or Argentan. I don't believe I said it was the base metal for everything; it was mostly the base for silver-plated flatware. I have old catalogs with front pages that describe the base metals. I'll try to make images of the pages to upload to the forum, but I'm horribly busy, so can't do it now. Silver-plated items often had N (Neusilber), M (messing = brass), or B (Britannia metal) stamped on them, in addition to the marks designating thickness of the silver-plate (I, I/O, 60, 90, etc.).

No problem..I understood we were referencing flatware for the base metal. My take on this is that Neusilber must have referred to a new elemental mix for Alpakka that made it "white"r. If WMF upped the nickel or zinc in proportion to the copper, they may have improved upon its corrosion resistance and color. I surmise Germany may have had greater access to foreign (colonial?) supplies of these metals during the era of development (and perhaps lower costs).

I found this piece on the site:
It does mention that alpacca is the base metal.

Quoting from: Marks of Berndorf Metalware Factory in Austria :

The Alpacca alloy was developed in 1823 by the German chemist Dr. Ernst August Geitner (1783-1852). It was very similar in its appearance to silver, but significantly cheaper. Therefore, this new alloy was first called "Argentan". It consisted of 20% nickel, 55% copper and 25% zinc. The new silver-imitating alloy soon became very popular. The Gebrueder Henninger (Henninger Bros.) proposed a similar alloy (5-30% nickel, 45-70% copper and 8-45% zinc with trace amounts of lead, tin and iron) which they called "Neusilber". Later both Argentan and Neusilber were used under the trade name of Alpacca (or Alpakka). The great advantage of the use of Alpacca alloy as the base metal for silver plating is that the appearance of the objects does not change significantly with the wearing away of the silver layer.

In general any silverware with name "Alpacca" is not silver and shall not be used in the kitchen as it is poisonous.