Surfing the net, I've run into a new (at least to me) acrylic, hobby paint producer from the Slovak Republic
http://mrpaint.sk/farby/lietadla/USSRConsidering that Czechoslovakia operated Soviet equipment, their interpretation of the Soviet color's should not be too far off.
One color that that got me scratching my head is their MRP-49 Light Gray Blue
http://mrpaint.sk/farby/lietadla/Československo?product_id=98 quote -
Russian aircraft Interior Cockpit, Wheel Well, Seat etc from 1960 to the present.
Could it be the famed PF-36M? PF-36 actually began to be used in the early 50's, but MR's statement could simply be the result of a hasty or incomplete result (Czechoslovakia did receive MiG-15's in the early 50's, after all!).
If the shade turns out to be close to the FS *4233, then we have an acrylic color that can be used to represent the AMT-16, AGT-16, A-36M and PF-36M range...
...or could it be one of the cockpit grey's used by different manufacturer's, e.g. the 'Yak Interior Grey', instead?
Also, their Czechoslovak AF range should be a godsend to any L-29 / L-39 fan...or were the VVS aircraft painted to Soviet specs?
Best regards.
Pete57