The tap base is smaller than the diamond holes. Not small enough so you can't get a good fix. But small enough that you can see light through the corners.
Hi,
I have an old cast iron bath. My old shower mixer gave up the ghost so I purchased a new one.
After removing the old one I discovered that the bath has square (or rather diamond shaped) holes. Now the old tap used to leak a bit around the base (and obviously wasn't original) and I...