Simon,
Yes.
Back in the early '90's the government of South Africa disposed of their Lee-Enfield spares and accessories. It was a huge lot, purchased through the efforts of a British arms dealer, so a large potion of which went to the UK, while further pallet loads went to the US through Victoria Trading Company (previously "J. R. the Webley King"), in Newfane, Vermont. All existing models of No. 4 bayonets and scabbards were represented, from original Singer cruciforms, to incomplete, unfinished and mint Savage manufactured spikes lacking locking mechanisms. The P.'07 bayonets and scabbards in the shipment also consisted of a similar wide range of manufacturers - from the more common Brit makers (even a few Vickers!), with a nice batch of Australianexamples, some of which were unissued and still in mint condition, as well as some mint double-stitched scabbards. There was even a small number of South African P.'07's made by AECO that I learned about too late to get one (still burns!).
Your photo of that grubby pile of No. 4 bayonets brings back memories. The paint on the bayonets appears to be identical to that which was slathered on many of the No. 4 bayonets, as well as a large number of the P'07 grips and scabbards. Whether this application was a South African effort or not, I have no knowledge, but with the multiple conflicts going on in that part of the world at the time, it is certainly a possibility.
It is just as likely, if not probably more so, that this sand color paint job is a relic of WWII. With as quick as the Mother Country was to divest itself of arms after the war, I wouldn't be surprised to learn that surplus arms and accessories ended up in several of those ex-Commonwealth countries in Africa. The hodgepodge-like, wide-ranging plethora of types and manufacturers, although a blessing to future collectors, does suggest to me a government's post-war effort to rid itself of its surplus.
Cheers,
Terry