(1916) Thomas Elder Washington Fantasy CWT Dog tag Medal

Does anyone know what metal compositions Thomas Elder struck these in and finishes he used? This one I believe to be silver, sort looks like an antique finish to it. I do have another one of these in my collection but forgot if its silver or white metal. This one weighs 11.39g and rings like silver. Thanks.
1
Comments
T. DeLorey reports that they were struck in sterling silver, german silver, silver plated bronze, bronze, brass and aluminum. Your piece appears to be a strike in german silver but it could be silver plated bronze which also have the antiqued finish. A close look may see peeks of brown on the high points or along the rim..
These were released in the middle of World War I and reportedly were meant to be pocket pieces for the doughboys after engraving, but the good captain noted that he had never seen an engraved example (at the time he wrote the article) and I will concur that I have never seen one with period engraving as well. I have seen two aluminum examples with engraving that undoubtedly was done at a later date.
Unfortunately this Elder issue is often called a Civil War dog tag which it is not. James Curto in his military token catalog anointed it (in error) as a Civil War identification tag and that mistake has hung with it ever since.
Thank you tokenpro for sharing your knowledge on this issue! Very informative!
I have still not seen or heard of an engraved piece.
Dug up my original file card notes but unfortunately I did not record the weight of my sterling silver specimen. A specific gravity test will tell you what it is.
Will do that this weekend. Thanks @CaptHenway.