For some reason, I was thinking that the special paint selections were usually limited to the same model year (of any color that GM offered that year on other models) or special mix fleet colors for a large fleet order. Argo's Blazer kinda looks like 72 GMC Terrace Blue to me - which I believe would trigger a special paint code when put on a Chev (if it was a GMC-only color, like Terrace Blue was). Not sure though...
Sharp Blazer, wow, would look great with the original gray plaid again
Certainly a one of a kind Blazer.