Isnīt soviet but it have some influences as it's Cuban. This is the MAYA CUBA, is a one-off build in 1963 using parts of a crashed aircraft and a single cylinder KB1 engine. It's possible to see it in the "Museo Nacional de Transportes La Punta" of Cuba. Incidentally I've a picture of it taken personally by a friend of mine in which the mascot in the front is different it has the shape of a rocket instead of the horse or so that shows your picture