Simplicity 3548 vintage sewing pattern, dated 1960.

Misses' One-Piece Basic Dress with Two Skirts, Detachable Scarf, Yoke and Belt:

Dress has front neck opening, kimono sleeves and back zipper. Belt is self or purchased. V. 1 sleeves are long and slim skirt has back kick pleat. V. 2 has 3/4 length sleeves and softly pleated skirt. Each view has detachable accessories. Bonus Basic. 

Size   12:

Bust   32 inches / 81 cm

Waist 25 inches / 64 cm

Hip    34 inches / 87 cm

Pattern is UNPRINTED, unused and factory folded. Envelope is in very good vintage condition.