After a recent tour of depots, in towns that my grandfather worked at in CA. (Barstow, Yermo, & Kelso). I recently purchaced my first model. I got the Bachmann "N" GP40 LOCO, DUMMY LOCO & CABOOSE - Union Pacific, Item No. 69853...  because it looked like the one my grandfather drove. Can someone please tell me what era/ca it was in use?