GB QV SG.8sc 1d Red Plate 20 (AJ) with Blue Maltese Cross

GB QV SG.8sc 1d Red Plate 20 (AJ) with Blue Maltese Cross. A 3 margin example of the much scarcer BLUE Maltese Cross, several offices were known for blue cancels, Preston, Truro etc, although for stamps off cover it is impossible to say with 100% certainty which office it came from but judging by the colour it most closely resembles examples from Truro.