South Africa Arc Titles: RAF?

[loupie1961]

I have got in my collection a series of South Africa arc titles, two worsted KD canvas titles with red lettering (one squared, one rounded ends), a pair in worsted green cloth, red lettering, and a single white lettering "South Africa" on green cloth (squared ends). I assume they were to be worn by South Africa volunteers serving in either the British Army or - more likely - the RAF. Is there any evidence of this? Thank you for your kind help!