INHERITANCE RIGHTS OF STEPSON FROM STEP MOTHER

The query relates to Hindu inheritance. My father died in 1983, leaving behind my mother (his second wife), my step-brother (from my father's first deceased wife), my own brother, two married sisters, I, and our respective families. He left behind a self-acquired bungalow at Agra ( UP), along with other movable and immovable properties. He had earlier executed a will on plain-paper, duly signed and witnessed in 1953, bequeathing all his estates to my mother. The said bungalow was purchased by him in 1963. My mother died intestate in 1995. My aforementioned step-brother also expired in 1989, due to natural causes. That implies that upon the demise of my mother, the surviving family consisted of my two married sisters and their families; the widow of my step-brother, and her children: my brother, and self and our children. My sisters have since provided us with Relinquishment Deeds for their shares. How will the bungalow shares be divided now. Family of step-brother getwhat share?