Jon,
Nicely done . There's one little piece of detail you've missed ( it doesn't detract from your painting) the small raised bar on the drivers side in front the small star. Is the centre of gravity marker. It should be painted yellow with a white C.on one side and a G on the other.
Harry's technically right (that's why there's a single version too) There was a A.F.D.C modification for a twin K. ( no. 20A* even a rear chassis mount no.28)It's very unlikely to have been air dropped simply due to the wieght it would have come in at over a 100lbs .( single mount alone is 25.5lbs and a k is 29.5lbs)
Some recce jeeps swapped out the k for the medium which gave a higher cyclical rate and weighed in at roughly 55lbs including mount.
The double K was done as an expediency and ironically has sold better than the correct medium vickers( not even on the website anymore.)
It does show up well after Normandy. It's likely to have been either a special forces version proffered or come across with the sea borne elements of 1st Airborne. (Not all para's jumped some had to swim
)
There are plenty of non regulation configurations that can be found in period photographs even in famous Arnhem photos. There's big holes in the technical data as the majority of inspection card that list vehicle mods were distroyed after the war( and during as the format changed repeatedly. Plus mods could be operationally specific)
As long as its a listed A.F.D.C. modification then It's in the realms of possibility .
So I just smile and give in.
Mark.