Hi Swinks, firstly we need to distinguish between Willliams parts and Bally parts. The parts which Freiherr posted a picture of are Williams parts.

Question: would the 20 cent coin plate be the same dimensionally as the 25mm but with the chute tailored to suit a 20 cent piece with say a 1mm gap either side as well as top and bottom.

Yes, I believe the metal plate is exactly the same for Australian 20c coins and US quarters. The only difference is the size of the coin slot which is slightly larger.

The white plastic chute is also exactly the same.

The window is also the same except for the text (see Freiherr's Photo for the Aussie version and my initial photo for the US version)

I believe all these parts are desperately needed. I think it would also be useful to have versions of the plate and the windows to suit Australian 50c and $1 coins, I'm not sure if these were ever made (can anyone confirm?) but they would be good to have anyway. If you were going to do these you would just have to change the size of the slots to fit $1 and 50c pieces and change the text on the windows.

Now, we also need the same done for the Bally parts which are not the same as the Williams ones. I'm not sure if anyone has sent you any Bally parts, but the Bally coin door doesn't use the plastic chute, it has a metal one which is part of the coin door itself so no need to reproduce this.

Or are the 20 cents and 25 cent parts all no longer available parts?

None of the parts suiting Aussie coins are available to buy.

Let us know what you have so far and we will put the call out for what you need. I think to do the job properly you need to have an Australian sample of both the Williams and Bally plates and windows, the chute can be a US version because it is the same.

Do you have the equipment to produce the text on the windows or do we have to find someone else to look after this aspect of the project?

Here's a couple of quick pics of the Williams and Bally coin doors so you can see the differences: