All Warsaw Pact aircraft had NATO fittings for fuel, power etc fitted as standard. You can probably work out why.
Perhaps it was for the same reason that they were all 7.63mm and ready to invade. I for one spent many summers on OPs Reforger, Lionheart, Crusader et al in the Fulda gap getting ready for the now (thankfully) un-prepared Russkis to wander through. Our bits fitted theirs, but for sure you couldn't put a Sov round into an SLR.