jim coughed up some electrons that declared:

Possibly OT but anyone know anything about and ideally where to get an
old style petrol attendant "sevice" bell ?
(the bit of black rubber hose? that you used to see stretched out
across the garage forecourts - when your wheels went over it it rang
a bell in the office to alert the pump attendant to your presence....)

ta
Jim

You could probably make one - all you'd need is some rubber pipe and a
pressure switch (something from RS or Farnell, or even a washing machine
water level switch (air pipe into water type) is probably in the right sort
of range.

Cheers

Tim