Can You Help Identify Any Of These ?

Absolutely any info would be much apreciated, as I know very little about them. If you can help, then please Email me. Thanks.

507. This mystery key has a most unique design! There is just one central pillar (instead of the regular two outer pillars) with a gap adjuster mechanism, and the main arm is literally designed around the pillar. The metal work is coated in matt black crackle finish paint that gives a nice matt "dried mud" effect, the base is ebonite. The large knob and skirt (suspiciously Marconi like) also appear to be ebonite. The spring tensioner is right at the back of the key.
The ebonite base measures 4 & 3/8" by 2 & 7/8" ( 110mm by 73mm), the knob and skirt are 1 & 3/8" and 1 & 3/4" Dia. (35mm and 45mm) so not a small key this.
Who made it ? Why the amazing design?

Mystery Key 138.
  • A large and sleek professional design but with no identification marks that I can see. The base measures roughly 6&3/4" by 3&1/8" by 3/4" thick (170mm by 83mm by 20mm) and the weight is just over 3lbs. ( 1.506 Kg).
  • Also has two interesting sockets for wiring. What type are they ?
    There is a hole on the right side that doesn't seem to have a purpose, underneath can be seen two threaded holes perhaps for bolting the key to a base. Also - note the two sockets for the wiring, I have not seen that type on a morse key b4.

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    usko...... This mystery key is a Flameproof key. Similar in design to the American J.H.Bunnell designed 26000 / 26003A keys. The owner - Walt / LW3EX is keen to find information on this intriguing key.

  • Walt has provided a little more information: "Body, Base plate & Lever = cast Aluminium. Shaft, adjusting Screws & Nuts = Carbon steel without any surface treatment. Knob & Skirt = Bakelite (a bit smaller in size than the 26003A model, but same design). Rear cable entry is a round nut in Brass with rubber gromet. Internal parts appear to be brass nickel plated."

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    "BK"