Union Of South Africa- -see Scan

  SG 31 1d Pretoria Printing  Bottom right Control block of four Issue 1 U/M ( faint trace of previous hinge in margin)                                                         Varieties 1/ " Perforated through bottom margin  " UHB V42--very scarce                                                                       2/ " Shift in vignette ''- bottom right stamp.                                                                       3/ " Printer's black mark"- in margin between bottom pair.                                                                             ( a fine exhibition item )