Featured Thrift Find - Los Castillo "Metals Castillo" brass/married metals plate; Can I polish dull front?

The one where they hammered the gold and silver into the cast iron, or something else? My brain wouldn't kick the name lose either - damascene.

 

Well, as you have been told, don't polish it if you plan to sell it. Let the new owner decide. If you are keeping it, then polishing it would only be an issue for you, though I would have it professional polished On something like this, if done properly, I am of the mindset that it would only add to the value of the piece as it would restore it to all of its original intended presentation.

As noted, it is mixed metal and combines copper, brass and silver to create the design. You can see the hammer marks in the metal and the number stamped in the piece is a design or inventory number. Los Castillo was established in 1939 by Antonio Castillo and his brothers. This piece is signed by Metales Castillo. They are known for sterling jewelry and fine pieces in "married metal" such as silver, copper & brass; Courtesy of The Little Book of Mexican Silver.

I would personally estimate the piece to the 1960's or possibly 70's when decorative metal pieces were popular - just a guess on my part, no research done, I just remember growing up with shiny metal all hangings...lol. The symbol or form is probably Aztec and should have a specific meaning - i.e. could be a marriage bit - if you can find the symbol. I do not believe it to be a random design.

Nice score!

 

It’s understandable how labor intensive this type of metallic item would be when hand made by artisans. Plus, neither silver or copper are cheap metals anymore.

Having said that:
Mixed metals have been around for centuries. Bronze is a mixture/marriage of metals that goes back to around 3000 BCE. My professional background is in the Physical Sciences/Geology. Therefore I see this differently. Technically, mixed metals are known as alloys of which there many. Yes, it does not denote the composition of the substance. A label that said “Mixed metals” of copper, brass and silver is very general and not definite like gold and silver jewelry content marks.

 

Looking at the surface with the stamp (the 4th photo), it looks like there might be a colored lacquer coating of some sort. There appear to be scratches in the yellowish area that reveal the silver colored metal underneath. If there is a coating, or other sort of surface patination, this would complicate any effort to clean or polish the piece.

From Oppi Untracht:

"An old process which was in use in Pre-Hispanic Mexico, but recently revived, is the process of making objects from a combination of separate pieces of silver, copper, brass, and a nickel alloy which are soldered together. The name metales casados or "married metals" was given to this technique by the revivers of this kind of work, Los Castillo, a family of silversmiths who work in Taxco, Mexico.
In this work, the metal is not a laminate as in mokume; rather, the various metals are joined in butt joints, next to each other, by their edges. This means that the pieces in the design must be very carefully cut out and matched so that they fit together exactly like a jigsaw puzzle to make a total, continuous surface, and the solder joining the parts is almost invisible......
The surface can be polished in the same way as any other metals, but a high luster produces a surface which is too light-reflective to allow the difference in the colors of the metals to be seen. A finish created by a wire brush buff revolving at a slow speed is therefore recommended. The matte surface so produced better displays the color differences."

Oppi Untracht: Metal Techniques for Craftsmen: A Basic Manual for Craftsmen on the Methods of Forming and Decorating Metals. Doubleday & Co, 1968. pgs184-186

He does not mention any lacquers or patination in the finish, but I wonder if it might have been a possible time-saving innovation introduced later in the history of the technique.