[GreenKeys] What's this Western Union keyboard device?

[Jim Haynes]

That's an interesting mystery - I hope someone can figure it out.]
Three-row keyboard suggests a telegraphic device.  But W.U. operating
tables tended to be much larger, as they had the line relays and line
current meters and duplex set and all that.  I know W.U. at one time
used a thing called Barclay's printing telegraph, but I have no idea
what it looked like.  I also don't know what the sending device of the
old glass bell jar stock tickers looked like.  There is one where it
looks like a piano keyboard, but I supposed they had had something more
modern as time went on.