The Russians might well have had Velcette MDD's as I've seen riders handbooks printed in Russian. But the picture looks like a modern mock up. There are several things wrong with the Velo and I can't even see any cable fitted. Ron
The museum photo shows two velocette motorcycles by the looks of it, Britain supplied about 1800 motorcycles to Russia in July or August 1944,maybe there are more that survive.
Information from a site on motorcycles used by the Red Army in WW2,Britain supplied 727 Velocettes,200 Matchless,and 679 BSAs,they were sent to Moscow,where this BSA photo was taken in the snow.
Two M20 motorcycles are for sale on Carandclassic.co.uk from Poland one shows engine number and contract plate, could they be from those supplied to Russia?