South Africa 1931 3d Shuttered Window Varieties, Both 3d 's

1931-33 3d Groote Schuur SHUTTERED WINDOW VARITIES on both 3d black & red and 3d blue, upright watermarks (SG 45b&45cd). Matching VF/U bottom arrow marginal positional pairs. The varieties on the right hand stamps, V3-R20/4. Scarce representation thus. (cv£300+).