I let a Lionel 219 AA Missouri Pacific diesel set go and regretted. It was at Daves, a train collectors house in Pittsburgh, when I was visiting my parents who lived there. I was living in Kingston, Jamaica at the time. I called Dave and told him I wanted it. My Dad went over and got it for me and I got on my next trip to the states six months later. Some times you get a second chance.
Recently I passed on a Lionel General 4-4-0 1862 set at a train show, not deciding I wanted one until thinking about it awhile. I was able to get an other one at the next TCA train meet in Ponchatoula, LA for less money. Some times you get a second chance.
Normally when I miss some train item I jot it down on my running train Want List so will be looking for it next time.
Charlie
Here they are. Notice the illuminated number board on the left I added and the wire at the back that provides power from the shown A unit to the dummy A unit lights.
Here is a Caboose I painted up to match the Missouri Pacific colors.