Simplicity #1946, copyright 1957 (per the vintage patterns wikia; no date on the pattern. Judging by the style and original price, I think this is accurate).
Size 12: bust 32, waist 25, hip 34.
"Jr. misses' and misses' one-piece dress with two skirts: A favored classic in 3 wonderful versions...the shirtwaist dress sleeved or sleeveless with slim or full skirt. All views have bodice with small collar, forward shoulder seam, front band detailing, button closing from neck to hem, top stitching. V. 1 has softly pleated skirt and short cuffed sleeves. V. 2 is a sleeveless sheath with side pockets. V. 3 is sheath with V. 1 bodice."
PATTERN CONDITION: Pattern is partially cut; the larger pieces (skirt pieces) have not been cut; tissue is in good condition! Instructions in good shape. Envelope is showing its age as we would expect--please see photos. This is a very usable pattern. Stored carefully in a protective plastic sleeve.