I guess photos could be considered "rare" if they belong to you. Here's a group of Soviet skydivers and an OSOAVIAKHIM instructor (2nd photo, the woman sitting in the center) posing near U-2 ( https://en.wikipedia.org/wiki/Polikarpov_Po-2
), main training aircraft of the organization.
OSOAVIAKHIM existed in 1927-1948, it was a paramilitary voluntary organization which was engaged in training of the civilian population. Klim Voroshilov was the official head of OSOAVIAKHIM and the institution was run by Soviet officers. The organization trained people in shooting, there were many sections for training snipers, radio operators, pilots, paratroopers, dogs and cavalry. Photo were taken before 1946, this is either wartime or late 30s. In the 30s the number of people jumping with a parachute was very small and even the masters of the USSR of that era had no more than a few hundred jumps, while modern skydivers can perform more than five thousand jumps, plus now we have access to safer parachute systems.