It looks like a test installation of some sort. The ironmongery on the tail looks like an anti-spin parachute. I'm guessing the boxes on the fin, rudder and tailplane are sensors of some kind...but not sure what.
Alas, I don't read cyrillic so I'm at a loss to provide anything more positive.
Could be that they were trying to develop a device that would automatically recover the airplane if it spun - or tumbled. The A-7D had something called "Post Stall Gyration" that was not a spin and you would not recover if you applied normal spin recovery techniques. It was proposed to install a sensor that would activate a flap if that condition existed so to allow recovery.
Obviously Russian with some old cyrillic typewriter characters, but it appears to read:
"Photo no. 3 - view the installation of the anti-corksscrew parachute and devices"
The wooden square on the rudder seems to be a kind of a protection against self opening of the round cover there. The second one of the rectangle shape on the fin seems to be either a base for attaching of a sensor or other device like the box with the actuator fixed to to the elevator. Perhaps it was an elevator angle indicator. So it could be a similar to the elevator device but for the rudder.
It is very likely. These seen three pieces like nozzles could be the air pressure sensors as well as blowing outlets with a kind of smoke to see the airflow around the tail.