Stereo Slide Viewers (various)

handpicked selection of four vintage stereo slide viewers, all with low voltage electric illumination and adjustable focus, for different slide standards and by various makers, all in good condition and with their original boxes, (1) Busch Stereo (Chicago), dark grey plastic body with red fittings, adjustable eye base, (2) Brumberger Stereo Viewer (Brooklyn, NY) in marbled grey plastic, (3) Bi-Lens 35mm Slide Viewer, produced by Sawyer's Europe S.A. in Belgium, oxblood plastic body, with original instructions, (4) Delta Stereo 3D Viewer, made by Lennor (Chicago), elegant stereoscope with ionised aluminium body, original instructions. (4)