The United States Mail Car No. 6428 was derived from the 6464 Type IV mold and has RED plastic Multi-block doors. Produced on a GRAY plastic body that was painted RED, WHITE, and BLUE with heat-stamped BLACK and WHITE lettering. Early production (1960-61) would have early AAR trucks with disc couplers, while later issues (1965-68) have late AAR trucks. There are three variations:
Variation A: Shiny RED paint.
Variation B: Flat RED paint.
Variation C: Lettering on one side only. This is a common factory error that occurs on flat RED painted bodies.