Even though the shaft of the replacement switch has a slightly different diameter compared to the original, it fits in perfectly -- no need to worry which way to install it as it is a simple on-off switch as I had to learn.

A bit tricky to fit it into the PCB as there are some wires in the way which also need to be desoldered first and then resoldered -- make sure to take a picture first before having a go at it.

A little switch that makes the difference was broken. Echo Fix supplied that part, fast and reliable. Now this ingenious machine makes infinite sounds again. Thank you down under. I will be back.