rqt mine was I think 33.6K
My first job was with a company that made the modems for BT's predecessor, the GPO.
The choice was 300. 600 or 1200 baud -- that's 0.3 to 1.2K 😮 You couldn't get legal modems from anywhere other than the GPO. And which ever modem you had, it came in a box about 15 inches cube -- which was mostly full of air. And you had to have two modems in that box (one for transmit, one for receive) and two telephone lines -- unless you went for the 1200/75 option (1200 in one direction, 75 in the other) which if I remember correctly had only one unit inside the box.