The Standard O 50' single-door and double-door exterior-braced boxcars were introduced between 1986 and 1992 by LIONEL.
They are based on real 1970's era freight cars.
The Standard O 50' boxcars are supposed to have Roller Bearing trucks, but have the old friction bearing trucks.
The only fine detail to add would be metal grab irons and some metal brake components.
Andrew