A gallery-style modernist home in Pound Ridge, NY, once home to late MoMA curator William Rubin and his wife, curator/art historian Phyllis Hattis, is back on the market for $4.85 million — down from its 2019 asking price of $6.5 million. Geometrically shaped, it was designed by the late architect Vuko Tashkovich, a protégé of…