Maybe a unique stamp, deep green??? 5 shilling SACC 186, indicate the colour as "slate"
UPDATED: 11 Aug 12:01
Apologies it should be SACC 188, - Asked by nfbooyse
11 Aug 11:43
Hi Frikkie it is SACC no 188 5s slate Thanks and sorry I will correct it now Christo
12 Aug 14:06