Tokomaru Steam Engine Museum comes with its own steam locomotives, historic railway station and a kilometre of private track.

It will be full steam ahead for one lucky buyer who snaps up a steam engine museum which comes complete with its own railway track.

Tokomaru Steam Engine Museum, south of Palmerston North, is owned by Colin and Esma Stevenson, who, after 50 years of collecting and lovingly restoring their steam engine collection, have decided to sell.

Colin Stevenson, 85, said they decided to call it quits because of health reasons and their age.

SUPPLIED After 50 years of collecting and lovingly restoring steam engines, Colin Stevenson, 85, and his wife Esma, 81, are selling up.

It all began in 1960, when Stevenson took it upon himself to preserve examples of New Zealand's industrial heritage, after steam engines became obsolete and were smashed up for scrap.

The collection quickly grew over the years, as did the demand from steam enthusiasts and, as a result, the couple opened a museum in 1970.

Three years on, former stationary engine operator Norman Kirk, who was also prime minister at the time, opened the first section of the museum's one kilometre railway track.

SUPPLIED The museum boasts 50 steam engines, including most types of stationary engines and two fully restored steam rollers.

The property boasts a three-bedroom house, garage, storage sheds, working steam engine museum complete with steam locomotives and carriages, the historic Tokomaru station, 50 steam engines and an engineering workshop.

Bayleys Palmerston North real estate agent Lewis Townshend said it was a "marvellous opportunity" to take regional tourism to a new level.

"Colin had a vision for the museum, and through years of dedication, brought that dream to fruition. It has enormous potential, and the next owner can just slide into the driver's seat."

Pride of place in the collection is New Zealand's largest steam engine, an American-made Filer and Stowell. The monster engine came from the Imlay Freezing works in Whanganui.

At the time, very few people had the opportunity to see this giant, Townshend said.

"The scrap metal workers told Colin they refused to touch the machine because of dangerous ammonia pipes under the floor, so it was his for the taking if he could move it - which he did.

"It was a mammoth haul, and Colin said no other task took him so much time and effort…the next owner has the chance to pick up on this legacy and keep it charging forward," he said.

"You could say, full steam ahead."

There was scope for The Tokomaru Steam Engine Museum to develop further, with more machinery to be restored, Townshend said.

"Colin and Esma have turned into a reality what children the world over fantasise about…most are happy to have a toy train set in their bedrooms - this couple has constructed that in their backyard."

The property was being sold by tender.