Typical Hemmi model 6.

A later Hemmi model 6 with a "Type A" cursor.  The window is slightly curved around a horizontal axis which produces magnificaton the the vertical direction only.  This is the only slide rule I have seen with magnification only in the vertical direction.  

Most of this specimen is wood.  The sliding surfaces are bamboo; everything else is bare wood.  It is owned by Wataru Tsuchihira who thinks it was part of a short-lived experiment in producing a less expensive slide rule.  The specimen is slightly warped.

Here is the end of the wooden model 6 pictured at left perched on top of an all-bamboo model 8: