CSA Catalog #6-PPa (SC #6P5), gutter pair 5¢ blue plate proof from the only known sheet (since broken up), signed PAK, slight crease in gutter as to be expected, a copy of the 1976 PF Certificate for the discovery sheet (Robson Lowe) at the time. The proof has a yellow cast compared to the regular issues, but is most difficult to determine without a reference copy. The only way to get a legitimate gutter pair since CSA 6 was cut into panes of 100 before shipping to the Confederacy. CCV $1,200.  $750.