FIRST OF AMERICA (FABK.O) ACQUIRES KEYSTONE First of America Bank Corp said it acquired (Keystone Bancshares Inc) for 25 mln dlrs. Keystone shareholders will receive 45 dlrs per Keystone share, payable in First of America convertible preferred stock having a dividend rate of nine pct. Keystone has two affiliates with combined assets of 205 mln dlrs. First of America has 7.9 billion dlrs in assets.