Way, WAY back in the late 60's through the 70's, AP and UPI provided teletype machines to radio and television stations. Those machines operated at a speed of 52 baud as I recall. The speed was limited, not by the mechanical teletype machine, but by the telephone lines which provided the "current loop" which fed the machines. High capacitance in the phone lines was the limiting factor. All radio and television stations in the same area were fed by the same loop. All machines in the loop were in series so each one received the same amount of current.
Many stations also had a weather wire teletype which operated at a slightly faster, 72 baud, speed.
In the 70's the news services abandoned the d.c. series loop and started using Frequency-Shift Keying with an FSK receiver at the receiving end to feed the teletype.
As a side note, these machines were workhorses. I can remember only one or two machine breakdowns. All of these machines smelled like machine oil.
Changing the ribbon was a nasty mess. Unless you wore Playtex gloves, you'd get purple or black ink all over your fingers ... and it didn't wash off easily.