Here are the packs. The larger I assume is from the IL-28. I don't think they had any other large Russian aircraft based there at Cairo West.
I found a MiG-21 canopy and some fuel tanks there and have found photographs of the MiG-21 stationed at Cairo West. I cannot find any reference to other MiG's or Sukhoi's being stationed there but they must have been. I also cannot find photos of a MiG-21 with a chaff dispenser that would fit these square chaff packs. All I find are launchers for round chaff packs.