Tankard with Incised CS or GS mark - George Sempagala, Abuja Pottery

Picked up this Abuja pottery tankard in a small antique shop here in Edinburgh today, usual impressed mark near the base of the handle however more unusually there is an incised mark to the base, CS. I haven't seen this before and can find no reference to any of the resident potters having these initials. Would love to hear your thoughts.

Update - The mark is GS rather than CS and the tankard was made by George Sempagala circa 1960-61.

Very nice