All privet.Ya sorry for bad English, I write with the help of an interpreter.I think it's a proper Krasny Oktobr.
I correct myself. The Dongo is a proper licence made Garelli Mosquito
You're right , Dongó produced in Hungary ! 955-1957 year license
Garelli Mosquito led Urbach László racer motorcycles
Mátra in 1939-1949
The Soviet Union also issued a similar engine in 1954-1955 under the name of "Irtysh"
Omsk Engine Plant Baranov .
I've seen such an engine , my friend , at the present time is a rarity .