Greetings,

 

I have an interesting Zeiss stereoscope for sale in ebay:

 

The open design and glass image holder make this viewer useful for MF transparencies, in addition to prints.  The focal length is a bit long (100mm) but it has focusing and interocular adjustment.  The lenses do not appear to be achromatic.

 

Anyway, I thought someone here might have an interest in this.

 

George