I can't remember for sure. I bought my latest rears and a front from docjohn sold them to me and I had them restored.
I know that there are two small spacers on each rear. I seem to recall the number 15 inside the wheels which may indicate the offset. I am sure that someone in the community knows the answer.
They are amazing wheels. Unfortunately when I had my latest set of rear tires mounted the chrome cracked in several spots on the lip of the driver's side wheel. I spent a several long days sanding these spots and trying to repair them. I was moderately successful and you can not tell there was ever a damage unless you are very close. Amazing what clear coat can do!