Surfing the net, I've run into a new (at least to me) acrylic, hobby paint producer from the Slovak Republichttp://mrpaint.sk/farby/lietadla/USSR
Considering 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?