Hi Neale;
The PIper part number is 453 966. It’s called a plug button in the parts book.
You can find one at many parts houses by typing the part number into your favorite search engine.
Prices are around $7 each.
This is a very generic part. We refer to then as Wilkie buttons; not sure of the source.
If you want to do a little sleuthing, you could measure the hole and see if your local hardware shore has one that fits.
Steve
