Update 8/7/20
Applied map gas on the shroud end and the end cap came off a treat.
I have swapped all the parts of my crown onto it and its much quieter now with the little WC shroud extended - but I don't think it will ever be as quiet as the crown due to the smaller Shroud on the WC.
so I am no contemplating drilling the WC shroud with say 3X 3mm Holes at the rear of the shroud on each side.
Does anyone know if this will help quieten it down