EXCLUSIVE JUST LISTED FIELDSTON HISTORIC DISTRICT  Spacious & Renovated 6-Bd. Brick House with Patio, Pool & Level, Grassy Yard    This spacious and recently renovated 6-bedroom, 6.5-bath, red-brick house was built in the neo-Classical style in the 1930s. It enjoys a wall of sliding glass doors spanning the entire back of the house, opening to an inviting wraparound patio, an above-ground pool and a fenced, level, grassy backyard.    Standout features include: a welcoming center hall with a curved cantilevered staircase; open-plan living room with wood-burning fireplace; family room; dining room; breakfast room; center-island kitchen with breakfast bar, 2 sinks and stainless-steel appliances (6-burner cooktop, 2 dishwashers, 2 wall ovens, 6-ft. refrigerator and built-in microwave); library/office; master bedroom suite with glass doors to a walk-in dressing room; master bathroom with double-sink vanity, glass-enclosed rainfall shower and deep soaking tub; finished basement with recreation room, laundry, full bathroom and maid's room; central HVAC; slate roof; private driveway; attached 1-car garage; 0.28-acre lot in landmark district.    Conveniently located for shops, well-known private schools (Horace Mann, Fieldston and Riverdale Country School), the vast greenery of Van Cortlandt Park and transportation to Manhattan (including express buses and the No. 1 subway train).