Last updated: 19 Jan 1997 Numbers Number Model Notes 420 1 S-6 470-473,477 5 GP7 480-481 2 GP9 490-495 6 GP38-2 500-501 2 TR2A 502-506 5 TR4A 510-511 2 TR2B 512-516 5 TR4B 520-523 4 SW9 524-526 3 SW1200 530-532 3 SW1500 533-536 4 MP15 600-605 6 C424