Ever since the South West Africa ½d. Official SG 023 with the forged transposed overprints appeared some ten years ago it has regularly featured on the odd auction. A used pair with a KGV1 expertising certificate dated 2006 was offered for sale on a recent auction. Fig. 1. Coincidentally it was exactly the same example which was proven to be a forgery in the article ― The forged South West Africa Official ½d. – SG 023a‖ published in the South African Philatelist of June 2013 Figs. 2 and 3. It was first noted by Murray Payne in 2006 and at that time given the KGV1 certificate and then sold at auction for £1460. Although catalogued by Stanley Gibbons in 2007 it was withdrawn in 2014 based on the evidence of a forgery. To Date the RPS, BPA and South Expert Committee have been unable to grant a certificate showing the stamp is genuine. The most recent auction price realized was £420.
Reference: Mike Tonking, The forged South West Africa Official ½d. – SFG 023a – South African Philatelist June 2013