The Pennsylvania N5C Porthole Caboose No. 6437 was produced from 1961 until 1968. This caboose was illluminated and was TUSCAN in color with WHITE "BLT 2-53" and "6437" heat stamped lettering on the sides. The two variations have to do with the trucks: The A Variation had early AAR trucks with one or two disc couplers, and the B Variation had late AAR trucks. This variation had only one disc coupler.