I don't know the answer to your question, I do see what you mean about the wheel nuts not looking centred and as it looks like they are all closer to the centre it could make sens as the Commodore pcd is small.
I would guess there is some sort of serial number on the Simmons centres and if you called Tempe Tyres they might be able to i.d. the pcd.
Just an idea.
Thanks Tom, the inside of the wheel has B45 cast into it and 628 stamped into it. I will try measuring with a digital vernier when I take the wheel off. Hopefully that will give me a good idea. I was just hoping someone might know what the error looks like between the two PCD sizes.