These stamps are often grouped together as “Hyphenated Rotogravure Pictorials” owing to their printing method. The change from inscribing the stamps “Suidafrika” to “Suid-Afrika” was completed over a long period, beginning with the 5s in October 1933 and not ending until the issue of the screened 4d in August 1952 (so this value not even included in this set). Because of this many advanced South Africa collectors deal with each value individually, rather than grouping different values to make sets that have large periods overlapping.
Please note the SG numbers of the 5s are a little unclear. The earliest printings of first issue are in black and myrtle-green and come with inverted watermarks. The later printings have the frames in shades of pale green, blue-green and grey-green and nearly all have upright watermarks. The 6d stamps come in three different dies. The used pairs of die II and die III are much more difficult to find than the SG catalogue would have you believe. There are also a number of distinctive shades of the 1s value, plus the 1948 printing has a distinctive mark in front of the gnu’s head and is straight-forward to identify.