A unique cylindrical casting by Pro Built LLC, Plainfield, Illinois. These examples were available as late as the early 1990's; not all that old but a neat presentation of silver casting and stamping.
And finally from the "Q" box; Queen Elizabeth 2. I have stayed strictly domestic to date but this is the only ingot in the "Q" box so it makes it to the blog. I acquired this from Tom shortly after we met so in some four years, this remains one of a kind, I have not seen or heard of any others.
Most likely dating back to the Queen Elizabeth 2 launch time frame of September 20, 1967, I can stretch what I see into the "Q" wrapping a reverse "C", possibly representing the ship's original owner, the Cunard Line.
Not necessarily a typical hallmark per my collection, and probably not domestic, but what a neat piece to post as the sole example from the "Q" box.