And, seven decades later, the 20-odd signatures of the men of the 61st Battalion can still be seen on the battle-scarred shell of the Japanese Type 95 Ha-Go tank that was captured in New Guinea at Milne Bay in August, 1942.

The tank has since endured pretty much everything that humankind and nature could throw at it, making conserving it a particular challenge, according to the Australian War Memorial's Senior Conservator of Large Technology John Kemister.

"The poor old tank has had a chequered career," he said.

The tank was being brought out of storage on Tuesday in preparation for the memorial's regular Open Day next week.

It was acquired by the memorial in 2005, and Mr Kemister and his team have since been working to restore it to the state it was in when captured.

He said it had been a challenge, to say the least.

"After it was captured, it was brought to Australia. It was evaluated by the army engineers, they pulled it apart to see how it was made, what was used, put it back together again, roughly, drove it over a mine to see how effective our mines were and then it was disposed of to a scrap metal yard, and it sat out in the open for 40-odd years," he said.

"Then it was acquired by the Melbourne Tank Museum and put on display there. Nothing was done to it other than giving it an artist's impression coat of paint on the way it should have looked. That was in the 1970s."

After the owner of that museum passed away, its collection was dispersed, and eagle-eyed War Memorial curators quickly picked up on its significance as one of the Milne Bay tanks and brought it to Canberra in 2005.

"It was identified as being a particularly significant relic of one of the first actions where the Japanese were actually defeated on land," he said.

This action was documented to the extent that historians knew that members of the 61st Battalion who had been involved in the action had scratched their signatures in the side of the tank.

"We could identify [the tank] by battle damage, strike marks on the tank, positively, and then when we got it here and we started looking at it, even though over the years it had been repainted, previous to that it had rusted and the paint fell off it, there was still paint remnants on it, and in those paint remnants were the 20-odd signatures of the guys from the 61st Battalion," he said.

He said one of the challenges in his job was restoring war artefacts that had been mistreated or neglected in the intervening years, through a lack of understanding of the object's importance.

"Part of the challenge with this is when we got it, it was a mess, an absolute mess, and there were many components and armour plates missing, so our challenge was to source either old components from other tanks or reproduce components," he said.

"It's a mixture of conservation, replication and restoration to get it looking the way it is now, so it's a judgment approach."

He said one of the best parts of the job was finding evidence of action on the tank, including the three Japanese machine-gun cartridge that were kicking around on the floor of the tank when they opened it up.

There was also a piece of palm frond from the jungle action site stuck under the bolthead, and the main gun shoulder-rest, although the gun itself was long gone.

It was also filled with dirt, rust and rubbish, including at least one dead rat.

The irony is that, although it is now pristine with a new coat of paint to protect the signatures, in preparation for display it will be worked on by set dressers to make it look authentically dirty.

"The way it's looking at the moment, it's rather brand new and spiffy with a few bullet holes and strike marks on it, but when it goes on display, we'll pass it over to set dressers who can throw a bit of mud around and stuff like that to make it look a little less pristine," he said.

The Australian War Memorial will hold its Open Day on Saturday April 6 from 10am-5pm.