The award of the Defence Medal to UDF members was not that uncommon - Field Marshal Smuts received one as did General Kenny van der Spuy. My Uncle was awarded one for service as a SAAF aircraft mechanic in North Africa but after the North African Campaign had ended - so he could not qualify for the Africa Star. I have a SAAF Navigator medal group in my collection with Defence Medal for service in the Middle East.
In my experience UDF members could only receive the Defence Medal in conjunction with the Africa Service Medal - to be awarded the ASM one had to have signed the General Service Oath (also referred to as the Africa Oath or "Rooi Eed" - due the orange/red tab worn on the epaulette). To be awarded the Defence Medal one had to serve outside an operational area but an area at least (possibly) subject to enemy attack, such as Britain, the Middle East east, etc. True, most UDF members served their entire time in operational areas and thus did not qualify for the Defence Medal but I cannot recall ever seeing a South African group of medals that did not include the ASM along with the Defence Medal. To go on active service one had to have signed the Oath so most UDF members received the ASM - most of the handful that did not were pre-war Permanent Force members who refused to sign the Oath and be prepared to serve outside the borders of SA. We did not have conscription then and all who signed the Oath (and received the ASM) were volunteers - irrespective of being PF, Citizen Force, "Hostilities Only", etc. Active service in the Home Waters of SA by the SAAF and Navy could, in certain cases entitle one to the Defence medal but in order to undertake active service one still had to have signed the Oath.
South African issues of the Defence Medal (and the War Medal) were identified by the suspender - South African suspenders had "double bumps" of equal size and shape on either side of the suspender bar while British and other Commonwealth issues had narrower "bumps" on the top (where the horizontal hanging pin for the ribbon is attached). Hope this makes sense.
All South African Campaign and service medals awarded for WW2 were officially named (only Rhodesians serving in UDF units had theirs named) and in cases carried certain suffixes (F for WAAF, W for WAAS, C for Coloured, N for Native, SRV for Southern Rhodesian Volunteer, SAP for the Police, etc.). I have a feeling the suffix M stood for Malay - bit strange with that surname though.
Dewald Nel, a researcher registered with the SANDF can perhaps assist - his email is
[email protected].