Thanks for sharing, Cromptonnut! Many parallels here wuth your story as I started with OO about the same time and I also love the class 33! I remember building a (very temporary) layout on the dining room floor to replicate the Hounslow loop, complete with Waterloo (2 platforms!), Barnes junction (single track!), Richmond, Hounslow & Feltham (terminus-ized) with a functioning triangle junction. those were the days!
Looking forward to hearing more. Cheers, Jon.