Last updated: 8 September 1997 Includes all MPI lease, test and demonstrator units and shop switchers. MPI was formerly MKRC, and M-K before that. Numbers Number Model MK 243 1 SW1u shop switcher, Boise SP 501-503 3 MK5000C test/lease MPEX 1501-1503 3 MP1500D demos MPEX 2001 1 MP2000D demo 5356 1 SD45u for loan to BNSF 5525,5527,5529 3 F45 5978-5980,5983, 8 F45u for loan to BNSF 5985-5989 9502,9532,9541 3 SD45 MKCX 9901-9902 2 MK5000C demos MPEX 9903 1 MK5000C demo