The "Wabbler" is a Morse Paddle manufactured by The Schurr Company.
Vigglin’ der Vabbler
It’s a shame they
don’t teach German in high school like they used to. This is
the language of great poets, dramatists, writers, intellects and
composers: Hesse, Rilke, Goethe, Brecht, Einstein, Weil, etc.
It’s been a long time, but my meager Deutsch saved me from throwing away the little strip of paper in the Schurr carton. I spent a bit of time translating the instruction sheet and I’ve found it quite interesting:
"The Schurr Key
(Please read this)
You’ve purchased a Schurr Paddle, perhaps on the recommendation of a satisfied customer. So that you may enjoy your "Wabbler" for a long time, here is some advice for care and handling:
The Schurr Paddle is made of brass. All contacts are made of a hard, silver alloy. The brass pieces are coated with a permanent lacquer to protect against corrosion. The Wabbler is designed for dry, indoor use. Clean with a clean, dry, soft cloth. Solder a plug that fits your equipment on the free end of the cable:
Common = Shield
Red = Dash
White = Dot
To clean the contacts, please use the enclosed strip of paper, or similar paper – never sandpaper! Turn the contact screw (1) slightly back. Pull the paper strip through once while lightly pressing the contact (2)(together). The paddle flanges (3) are cleaned in the same way.
The spacing of the contact lever of hardened,
polished steel is adjusted with the contact screw (1). You can
set your desired contact spacing. The spring stop (4) can be set
to your preferred "feather touch."
And now, I wish you much pleasure with your "Wabbler." …DH2SAA"
Listen to Der Wabbler: 
The Stellavox Motion Picture Recorder
The Stellavox became
available in 1958, and in some places, the little recorder is
still in use! 
It had a
single motor and belts & pulleys. The motor was not servo
controlled, but controlled by a governor that tended to spark.
The sparking was a source of noise. Drag was supplied by a felt
disc. Power came from two plug-in lead acid battery packs
consisting of two, two-volt cells each, a total of eight volts.
The battery packs were recharged by a separate charger. A sync
pulse was applied to the tape on one of two tracks, allowing
synchronization with the camera. The factory-supplied pulse
proved to be too high in gain, and too difficult to filter, so
the recorders were retrofitted with "Rangertone" after
they were imported from Switzerland. ("Rangertone" was
a U.S. standard for motion picture camera/magnetic recorder
sync.) My unit has four heads: Record, Playback, Sync
record/playback, Erase. 7 ½ i.p.s. was standard speed for the
era.
Motion picture recordists were used to listening to a photoelectric cell that monitored the optical sound, so when magnetic recording came into being, the playback head was always checked during recording to verify operation, and still called "check the PEC" (PhotoElectric Cell). Amazingly, the Stellavox could be operated without monitoring because there was a built-in feature that actually switched a low-impedance microphone to the audio output for use as a makeshift speaker to verify recording!
With its single motor, small reels and odd batteries, the Stellavox quickly fell out of favor with the major studios, but the low cost, portability and simplicity of design made it popular with news, documentary and low-budget filmmakers.
Ryder Sound in Hollywood was the primary importer and dealer of the Stellavox. Ron Cogswell, now retired, was the chief engineer at the time. He later became General Manager, then an officer with Nagra.
Cogswell says, "We tried to discourage them, but the documentary filmmakers loved the Stellavox. Jack Douglas used them all the time and actually recorded the Viennese Boy’s Choir with one! The show aired on NBC."
Cogswell says that a big problem with the lead acid batteries was that the electrolyte froze in cold weather, "I warned them about it, but they took the little machine to Mount Everest. They wrapped it in a blanket, made their recording and let the damn thing freeze."