I think there will always be confusion or conjecture on this one.
Here is more of what I've found
The Strela, which means "Arrow" in Russian, is one of the most coveted watches in Russian horology. Introduced in 1959
The movement in the Strela was Poljot caliber 3017, a 19 jewel based on the Venus 150 chronograph movement. The movements made around 1965 have the following serial numbers:
- 1959 - 1963 Strela, Sekonda, up to 19000
- 1964 - 1965 Strela, Sekonda, Poljot 19000 to 31000
- 1966 - 1967 Sekonda, Poljot 31000 to 42000
- (Movement number divided by 5000, then add 1959 to get year of production).
I always stand to be corrected.
Cheers,
Buster