"This is weird...the suction valve is screwed in on both sides, so you can't move it!" - Yes, but with the arrow at the bottom of the celluloid dial, it would definitely seem as if the dial could be turned to divert the suction through the handle, like the Air-Way. The Air-Way has a screw on one side of the dial as well. It may have even had tools. Could possibly this Dizer have been produced after Air-Way's patents ran out? It was such a good design, I wouldn't be surprised at all. Now that their patents expired look at how many "copycats" we now have of the Oreck. There's the Bissell ProLite/Kenmore e4, Hoover Soft & Light, Elektrapure, Maid-Lite, Avanti Homemaker, etc. Is the suction power of the Dizer comparable to the Air-Way Sanitary System? I love this machine! With the painted handle, it is reminiscent of the 1932 Green Goddess.