[Mark70Z]

I have a question in regard to the Topps Brooks test discs. I try to keep up with the items that have been for sale in regard to Brooks, especially w/ test issues, and both of the attached photos were once in a past H&S auction. All of these discs pictured were described as '67 proof discs, but are they '67 or are they '68 discs. The one in the SGC holder states '67, but I'd like to know if this is correct or not.

Thanks in advance for your help.