Lid badge push nut size

[Bruce]

I believe 1/4". But don't quote me on that.

 

[Cody Bratton]

What is the correct size the white ones are supposed to be? And what is the axel size of the tank roller?

The shaft is 1/4" but the original white piece (cap) is the same size as the caps on the wheels.

 

[Samuel]

Amazon.com

Thanks Bruce.
I ordered these today.