"The machine gun on the back of the jeep is plastic but the rack that holds it, the ammunition box, the ammunition clip and belt are all made of brass," he said.
It's a basic kitset that Mr Andrews has added to and, when completed, it will be part of a diorama featuring a desert scene, including remains of a bombed building and other figurines, one of them mounted on a horse.
It's a piece of work that has taken him more than 200 hours to get to this stage. There's just one piece of refining to be done to one of the figures before it's finished and that's putting a pair of binoculars in the left hand of the gunner stepping out of the jeep.
"All the work in the international competition is judged online, using pictures of the model. Through the building process I've had to post online what I was doing with the model, its history and all that. So the judges will have all that information," Mr Andrews said.
The results should be known early in May.
His passion is 1/35th scale military models and he said he spent as much time on researching the individual pieces he worked on as he spends on putting them together.
"It's all about understanding the history so I can get the colours right, the equipment right, and so I know that what I'm setting up is historically accurate. But the thing is I get such joy out of doing it that when's it done it's great to show it off at an expo like this."
He works on his hobby in the evenings and on the weekends.
"I'll use a magnifying headset for the really fine and tricky work. But it's so detailed it's not something you can do for more than a couple of hours at a time."
Mr Andrews said the problem nowadays was in sourcing the models he wanted, because over time the shops have gone and club memberships have dwindled.
"The club I'm a member of had over 200 members once. We're currently about a 10th of that now. A consequence is the model shops have gone out of business or they don't stock as much stuff as they used to.
"Probably about two-thirds of what we're showing at this show has come from overseas. so you'd have to say thank God for the internet."
And when he's not in his modelling room, Mr Andrews and his wife operate a massage therapy business in Palmerston North.