I am not sure which category this should be placed. I have a printing press plate of the Flag Code by the American Legion. It is the last of the updates in respect it reflects the acknowledgement of the 50th state to the Union on July 4,1960. The plate measures 11x17, weighs approximately 11 lbs, and I think it is made of pewter.
I do not have any history of prior owner. I acquired it when cleaning out a garage from a house that I purchased out of foreclosure. It was hidden behind piles of cardboard boxes and other trash.
This is a vintage mid 20th century original plate for printing. Plates were the most common method for printing in America prior to technological advancements. The metal plate would be 'carved' in reverse to enable printing. The metal used, known as 'type metal' is made with mostly lead (hence the weight) with antimony and tin added for durability over time and usage. The subject matter of this plate is the Flag Code from 1960 that was published for reference by the American Legion. Although interesting and 'unique' unto themselves, printing plates are not highly collectible nor particularly sought after on the market. The estimate is based on actual recent past recorded auction sales of comparables. Retail 'asking prices' can be higher and vary.