Folding Pocket Stereoscopes (various)

set of three collapsible metal stereoscopes, all in mint condition and each with its original case. (1) Casella Stereoscope London, cast aluminium body with adjustable eye base, makers label "APX", in brown leather case, (2) black painted solid brass body with chrome plated steel legs, engraved "T.H. Rosenberg, Joh. W. Lummert, Berlin", like new in a black case, (3) Carl Zeiss stereoscope, comes together with the original set of 10.5x6cm Zeiss stereo cards and a dark brown leather case. A fine collection of pocket stereoscopes with high quality lenses