Franklin Mint The Official Emblems of the Great American Railroads in Sterling Silver Ingots that each weigh .76 oz. each along with enamel colors of the 50 different railroads that are represented. These were minted from 1979-83. each ingot measures 1.75" x 1.125". At time of issue, the ingots were $35 each or the entire set was sold for $1750. Marked on the side of each ingot is as follows: Sterling © Franklin Mint Emblem in a small square followed by the number "79" "80" "81" "82" or "83" in a square, all dependent upon what year each ingot was minted. My guess is that they minted 10 different ones each year from 1979 to 1983 and eventually sold entire sets once all 50 were minted and able to be placed in the collector cases such as we have here.