cleaned up the ‘group’ first time;
coffee temperature after cleanup rather low, so been investigating a bit and got to realise the joint on ‘heat exchanger’ was failing;
on Valente 1966 patent application is clearly noted the underside of the bell has to be sealed – so cut,drilled and sanded down a champagne cork to a +-3mm thick torus and added this in under the bell shaped heat exchanger element;