First, about how many streamlined and heavy weight passenger cars can a single F7A pull? Second, can you point me to an online guide on how to determine if a freight car belongs to the 1950's? I'm on vacation right now. I'll be having time (and money, hehe) for my layout when I get some database and e-commerce solutions done for relatives. Btw, I'm still a student and blissfully spending vacations on my HO layout. Oh, and I'm just a beginner with this model railroad hobby. I have a 4x8, and I have no plans of expanding it right now.