Class 73
The class 73 electro-diesels, built by BR's Southern Region, can take power from the 3rd rail or from a small diesel engine. Four locos were transferred to Birkenhead North in the 1980s for use on Merseyrail infrastructure trains, and it is one of these that inspired this model.
This model was part of a limited edition run produced by the now-defunct Lima of Italy for Hatton's Model Railways in the early 1990s. It depicts loco 73901 wearing Merseyrail yellow and grey colours. As far as I know, this is the only ready-to-run model ever produced of a Merseyrail train.
Lima's models are quite basic compared to the current offerings from Hornby and Bachmann, however this model (obtained from a seller on eBay in 2005) looks OK by the standards of the time and is a good runner.