Do you have access to a sheet metal supplier?
Are you planning to create your own?

Mate,
All you need to do is measure the hole and cut a piece of 12.5mm ply to fit. Or cut a piece of sheet metal 30mm larger than the hole and bend all the edges over 90 degrees, 15mm deep. Get a lock and measure how far down the hole needs to be for the tang to hit the metal stop, drill it and fit the lock. I've made loads for wedge heads and Williams games doing the above and never had a problem doing it. And every game needs a slightly different sized door. I don't know if they warp over the years, but no two are identical. So you are better off making a bespoke one anyway.

Ok, i would make a cardboard template for sizing a few millimeters just loose of the actual (tight) fitment and make the 90° bends just a bit short of what fits in the u-channel on the bottom for sizing all around the small bends of the perimeter. Cardboard is a cheap disposable template.
Check to see if you are square measuring your corners diagonal for a proper fit is a start to what you are dealing with.

Do you have a sheet metal brake? If so then you are ahead in a few steps in the work cut out for you. If not then you can make a makeshift brake with some lumber/timber and some c-clamps can get it pretty close to what you need.
Some hammer and dolly work can help with some aesthetics if wanted/needed.
Although not original oem,you mentioned wood which can be used to accomplish the same thing and should work just as well for you. Whatever is comfortable in your skill set is what direction to go.

This guy on ebay sells new wedgehead doors, 2-player doors, and 4-player doors to fit Gottlieb games. Here the link for the 2-player door. He provided the dimensions in the instructions. You'll have to see if his is the exact size you need:

ebay.com link: 2 Player Gottlieb Pinball Machine Repoduction Back Doors Backdoor Not Orginial

It sounds like you want to make your own and you're not from the U.S. so shipping would probably be a problem but here's the information anyway.

These look perfect!! Thanks Hoov

FYI

If you buy more than one door shipping is cheaper

Nice work.

Now if you's sell them for $20 each you'd sell a dozen. I need one for a Card Wiz

Yea shipping would be $25 etc. still...I need 1

FWIW, Jeff also has the 2-player doors available:
http://www.everythingpinball.com/pinball-parts

Shipping is usually around $10.

(I just bought one for my Quick Draw - it's very nice.)

I have used him before as well. Good guy, was the first 2 player door he made, gave good shipping price on two.

His website does not show 2player, I sent an email.

That's correct, it's not on the website. But he has them.