I just saw this:
They look like IGVs but I'm not sure. What could those be? Do you know the engine?
You have a very interesting find there! It is in fact not an engine from a B707, but a Kuznetsov NK-8 from Russia.
It was used in Ilyushin Il-62 and Tupolev Tu-154 aircraft.
As for the intermediate vanes, it is my understanding that their purpose is no more special, than to just stabilize the airflow entering the bypass section of the engine.