||The meaning of the acronyms are unclear but are likely political in nature. Because of the choice of the coin they're probably Nationalist. The seller suggested that SA may stand for either South Antrim or South Armagh. No guess as to the meaning of GC. A second contact of mine seemed faitly certain that SA stood for South Antrim. He felt the GC might describe a specific paramilitary unit, probably of the IRA. (Group C, perhaps?). Both men felt the inscriptions were political. Purchased from Mark Henderson / Belfast, Co. Antrim, N. Ireland (Ot. 28, 2017) ($14).