South Africa 1913 KGV 1½d Tete-Beche Heart-of-Sheet Gutter Block

1913 KGV 1½d chestnut TETE-BECHE HEART-OF-SHEET GUTTER BLOCK (SG 5a var/CC 4g var). F-VF/UM block of four with vertical & horizontal gutters congruent. Light horizontal fold at centre. Most attractive, a frustratingly elusive representation! Rare.