Originally Posted by
old,not bold
Thinking back to the pre-war £20 bangers of my youth, that would have been the hooter and/or, on some, the control that operated the semaphore direction indicator.
Could also have been a hand throttle. Or (for the real mechanical buffs) the gear control quadrant for a preselector gearbox. 10 bonus points if you know how to drive one of those
Large cars (especially American) in the 1950s also had the gearstick mounted on the steering column ("column change").