Note to all:
If you can’t measure the “fill amount” BEFORE installing the bottle out of sight:
Buy a “replacement” bottle and measure IT.
And, once you have that critical “Number of Ounces”, start looking at laundry bottles and their “measuring cup” caps.
Find a cap with the same capacity as the dispenser.
But: when do you refill? Is the level always the same when you start the super-critical “Measuring of Liquid Soap”, or will the “top off” amount vary over time?
Maybe a Nobel Prize is in store for the person who finally cracks this global quandary!