Metal Printing Plate of Antique Automobile, early 1900's

Description

this was found in a junk drawer of assorted pins/buttons at an estate sale. I do not know it's age, but other stuff was 1890's-1920's range.
I do not know what type of metal it is, perhaps lead?
appears to be a printing plate showing an old automobile
it's 4" long, 2" tall, has angled corners as shown (about 1/8th inch thick)
it's worn and pitted
Code JSB159