They were not so much a promotional item, as it was a part work magazine, whereby you got a magazine and a train item every week for the duration of the series, which was something like 45 or 50 issues. As the others have said, they are made from thin tinplate, but they are very colourful and have the virtue of being cheap! Most of the people I know who have them have removed the clockwork motors, truly the most awful bit of all of it, and fitted ETS electric mechs.
Cheers, Mark
