SOME RETRO-TRAIN WATCHING. Yesterday's grading session at the coffee house with a view of the tracks was interrupted by numerous train movements. Union Pacific have several series of hoppers with reporting marks CMO, the AAR three-letter no-ampersand Class I required format for CSTPM&O, the old "Omaha Road." A westbound freight had a GE diesel numbered 3984 as the trailing unit. The next of the series is not like the others...