Found the loose lens at a show for $30, no camera. Glass in great shape, took it apart and cleaned all of the surfaces. adapted to Leica mount using a Canon 50/2.8 Focus mount, retaining rings from an Industar-61 as a barrel, and focus ring from a lens off of a Kodak TLR for a trim ring. Wide-Open at F2.8 This is a 5 element in 4 group lens, looks like Schneider modified a typical Tessar by splitting the front element into an air-spaced pair. It is sharper than my Zeiss Tessar 5cm f2.8 of the same period.