Wheels on book car

[ashbudd7]

Morning everyone, just a quickie-

Does anyone know the make of the wheels on the book car?
I was given a set when I bought my chassis that I was going to use as just build wheels but I think I might keep them for a while, BUT I'm missing all of the centre caps and was wondering if I could source them anywhere or if I'm going to have to resort to making some.

Cheers

Ash