Hi Ash, makes perfect sense, didn’t realise the thicker part of the studs were moulded rubber. The moulding seems to be shown on the K3 as well, so may get a couple of replacements as they must be there for a purpose, perhaps to stop vibration
I’ve bought an new pump off of Frank in Germany as old one is badly scored. I was concerned about the wear to the external portion of the pump body as to what caused it. You can just see it on the outside of the pump in the photo.
Thanks again for your help 👍