B., I do not have that answer. You would need to ask them. They can be reached at
gmhc@gm.com.
I am also trying to get in contact with Mr. Don Meyers who is a GM Historian and who lives in my area, to see if he might have access to any early 60s databooks. The books are quite thick and I would imagine getting a copy to you would be labor intensive and cost prohibitive.
Dave Boboltz, Waterford, MI, 1964 K1002 305E