[GloucYeoman]

Ken,
This looks like a modern No5 dress RAF wing to me. The only time the RAF have solely been employed in the AD role was:
1918 - Ammo dropped on Western front LofC.
1919 - Somaliland and India during "Mad Mullah" campaign.

Otherwise AD was/is RASC/RCT and RLC. Notwithstanding the RAF suspended Mess Dress during WW2. The RAF style above blue half wing badge No5 Mess Dress is badge is an RAF and not an army badge.

The Army AD crews consisted in the main a Cpl Despatch Crew Commander and 3 crew in Dakotas from Burma 1942 onwards and including the Stirlings a crew of 2 AD at Arnhem in 1944.... and 2 AD pers in Liberators during the Rhine crossing drops 1945. The only exception for AD RASC not being on board would be clandestine small stores from a Lysander etc on some SOE duties. Therefore, the existence of RAF doing Air Despatch Would have been 1950 onwards with "Loadmasters" wearing the 'QM' brevet; 'LM' in 1970 and 'RAF' 2004. However, they are in charge of the load and AD army pers and it is the Army only who do the actual Air Despatching.

In short the Army do Air Despatch and wear their double AD wings since a wing was designed in KL and a brevet was introduced (War Office Dress Commitee 1956). The RAF relied on AD RASC companies to supply the crew. There were no RAF dispatching any stores apart from clandestine Ops and that would not create a special badge, as it was more often than not the SOE op throwing her/his SEAC pack out before she/he followed.

I also believe even if the RASC would be ludicrously allowed to wear what looks like a chest wing AD RAF style for their early Ops there would be a pic of one from the 900 pers in the group.

Hope that helps, and love to be proven wrong.
Regards,
Matt