This picture is of a duplicate tag I made from the original one on my low mileage 1960 Thunderbird. The tag was retained to the engine by the upper water pump mounting bolt on the left (driver's) side. The tag measures 3 ¼" dia. with 1" numbers and ½ " letter 'D'. The original tag was in rough shape which made it hard to tell exactly what color it was. My best guess is that it was a dark brown cardboard painted black when the engine was painted. The mystery is that the attaching bolt was not painted black. Possibly, the tag was cut from material that was coated to make it more durable. I believe the number 296 represents the production day of the engine. My car was built Oct. 27, 1959 which works out to day 300. An engine production day that is slightly earlier makes sense.