There were a good number of model railway enthusiasts present and if stocking up on bus timetables from the 70s and old tube tickets is your thing then this is the place to be, but otherwise there was a lot of interesting stuff to see there plus a selection of talks, presentations and vintage films to watch too (the talk on London's disused underground stations was very interesting - no really).
If old tube signs are your thing then you won't be disappointed!
The collection also includes a large selection of scale models of various stations etc, with the Oxford Street undergound station one being one of my favourites. There's so much stuff under our feet!
The only small disappointment was that they hadn't opened the poster/art work department when I visited which something I particularly wanted to see. Maybe next time!