I've just purchased some rubber switch covers for the toggle switches at the helm of our 54.
The nuts on the covers were a little "green", and I had damaged one of the rubbers when removing the spherical toggle, so a new set of covers (including shiny new nuts) was in order.
The switches are Apem 600H Series (eg 637H) and the rubber covers (sealing boots) are also from Apem, they are part number U1565. To replace all the covers was about USD50 from Mouser.
For the more adventurous there is a range of sealing boot colours to choose from, eg red, green, blue, white !
I stuck with black.