Yes! Note that it's a lowercase "c" so apparently it has nothing to do with the uppercase "C" designations. Interesting slab. I have a couple later ones with Canadian coins and I don't recall being upset about the grade given. I'll have to dig them out and see how I feel about them now.
A2 is the Grade: Full Strike / Brilliant Surface. the c is "commercial" not flat. If it were flat, it would be A3-64
The C has to mean something, one would have to refer back I think to the reference in the Photo Certs. The only two photo certs on the link are Morgans.
It's "commercial" on these ACG slabs, meaning that it is a commercial grade. I don't think circulation makes sense for an UNC coin.
Got it; I think commercial sounds find. The term "Market graded" was probably not as prevalent back then.