It took four men a year each to build but in the eyes of its owner, it is never truly finished.

Retired Wolverhampton electrical engineer Keith Thompson will this weekend show off his pride and joy to 18,000 visitors at Birmingham NEC.

His model railways have been labours of love for more than 50 years and take up a whole room of his home in Coalway Road, Penn. The father-of-one’s pride and joy is his 16ft scale model of a favourite part of St Agnes in Cornwall, featuring cottages in a stepped row.

And he said today’s children could do worse than put down their computer games and pick up their modelling kits.

Mr Thompson said: “I don’t dare to think how much I’ve spent on all of these over the years but one of them is insured for £10,000. I’ve always loved train modelling, ever since I got a little clockwork set when I was six or seven.

“A lot of people just set up their locos and they’re in heaven but I prefer to build the scenery. I find just running the trains boring.”

Never one to rest on his laurels, Mr Thompson has built scale models of railways in Spain, Canada and Dorset as well as his Cornish freight line modelled on the trains that ran in the 1920s.

He is ably assisted by three friends who take it in turn to assist with working on each other’s sets.

Phil Crathorn, of Glengarry Gardens, Finchfield, and Stuart Allun, of Alexandra Road, Penn, join David Mee from Bewdley and Mr Thompson once a week to brainstorm and put pieces together. They worked for four years on the St Agnes model. Tomorrow, Pop Idol judge and train enthusiast Pete Waterman MBE will help Warley National Model Railway Exhibition celebrate its 41st annual show at the NEC.

The record producer, whose discoveries include Kylie Minogue, will open the event at Hall Five of the NEC and it will run tomorrow and Sunday.

It includes more than 75 working model railways, preservation society demonstrations by modelling experts and more than 150 specialist suppliers, with a total of 350 stalls overall. One-day tickets costs £10 with a two-day ticket costing £18.