[njsteve]

Found this Formula wheel during my ongoing garage cleansing. It's in the original box which has a USPS ship date of March 3, 1975. Box has the 487290 label on it.

The wheel measurements taken with a vernier caliper are as follows:
1.150 when measured against the seam
1.120 when measured against the front and back round sides.

When you wrap a standard business card around it you get a 3/8" gap. No molding code on the backside. Has the double seam visible on the outer circumference.

My question is this: is this an early version 1970 thick wheel that was boxed up and sat around on the shelf in a GM warehouse til someone bought it? How long was the 487290 part number used? From 1970 onward til???