Poljot Aviator, Aviator, what is the difference?

While I was in the process of finding out more about Poljot pilot watches, I found two similar models but with different branding. They are pictured below:





One is branded a 'Poljot - Aviator', while the other is branded 'Aviator'. The logo is different too. The first one is rated at 100 meter water resistance, while the second one 50 meter. This seems to suggest that the Poljot branded one has screw-down crown, while the other one does not have.

Actually, based on other people's experience, it is better to not have screw-down crown for a manual wind watch. It is a nuissance. Imagine having to unscrew the crown for winding everyday. This can also contribute to wear and tear of the thread.

I read somewhere that after Volmax bought the First Moscow Watch Factory, they created different brands. The brand Poljot is sold exclusively in Russia, while the brand Aviator, Buran, and Sturmanskie is sold outside of Russia. So I think maybe the first watch pictured above is the Russian version while the second one is for market outside Russia.

There is however, another theory. The Poljot branded one may be an old stock. It is made before the demise of the First Moscow Watch Factory. The second one is made after the factory is bought over by Volmax in around 2004. Both watches are made in Moscow by the same factory and possibly same bunch of employees. It is said that the Volmax has increased the QC somewhat. I got this knowledge from a fellow forummer in watchuseek.com. The prices of these watches are identical.