Thank you Dront, for that information. I didn't appreciate how rare the Orbita was relative to the Kosmos. Feeling very lucky to have both in my collection.Actually it is not an ordinary 1MChZ 2415 , rather pre-2415.As Kosmos is pre-2416. Орбита movement performes some differences from ordinary Poljot De-Lux 2415 . It was improved , transforming into later serial 2415 (De-Lux). And Орбита is much , much rare piece than Космос. Hardly a dozen known . Presumably it is 1961-62 year production.