Chicago Line Toy Company no. 1670 Tank Car, NYC Liquefied Hydrogen (detail of right hand end).
Bill Fuller tells me that he bought this car for $25.00 from an advertisement in the June 1991 edition of Classic Toy Trains magazine. . The bottom of the flat car floor as well as the plastic trucks (bogies) have the letters "MTSI" and "Made in Korea" molded into them.