There are two small "rings" there on older wealded turret kv-1s the tank at the samur museum has them visble
http://www.peachmountain.com/5star/M...sian_KV_1.aspx 4pics down
actully ive sort of answered my own question here as this is the first good photo i have found of a wealded turret kv

the pistol port i have pics of of now but from a kv-2 i trust there the same type its a round bar with a mushroom at the end with a chain in a straight(not tapered at lest from the outside) hole