Butterick 3957; ca. early 1930s; Men's or Boys Slip-over Pajamas with or without the Fly. Description: Pull-on long elastic waist pajama pants with or without front fly. Pullover pajama top with long sleeves, patch chest pocket, neckline band. Suggested Fabrics: Broadcloth, fine Cottons, Percale, Wash Silks, Outing Flannel. This is a vintage pattern Deltor patented in the US August 19, 1919, January 23, 1923. Featured in Butterick Fashion News, January 1932