Help! I just acquired two open-ended slant-sided rectangular boxes stamped Wagner Ware and made of cast aluminum, with straight sides about 1/8" thick. These are not numbered and are two different sizes: (1) 5-1/4" tall, with about 4-1/2" by 3-1/4" top measurements and 4" by 2-3/4" bottom (2) 3-3/4" tall, with 3-3/4" by 3" top and 3-1/4" by 2-1/4" bottom. A fellow shopper thought these might be used to fill cardboard ice cream cartons -- you put the carton inside the Wagner piece and then fill it to keep the cardboard sides from expanding. These appear to be old and are obviously a matched set -- I cannot find any information on these anywhere. Would any forum readers know what these are?