[GreenKeys] Well, it's not a Teletype ...

[Jim Haynes]

The McElroy sticker pretty well nails it as a high speed Morse
transmitter.  The round shape of the reading head is also quite
suggestive of that.  I think McElroy marketed some products of
Boehme and others through his company.  The Boehme keyer has that
circular shape of the reading head.

Seems likely RFL simply won a contract to deliver some high speed
Morse equipment, and repackaged McElroy/Boehme machinery in a box of
their own design.