Excellent discussion. I have to dissagree with Simon though. The Scotsman, The Mallard, sure I have seen them in a museum.
I would class myself as a newbie/returner (returning from say age 15). What I remember most are the BR standard classe tanks from being taken to heritage railways as a kid. Those are the ones I wanted to get and with them recreate those day trips.
I guess it's generational, and based on an individuals background Vs hard business data.