Be nice to have consensus on acceptable 20K test values for Resistor plugs and non-resistor plugs? 
Best to test hot or cold?  
Cold 20K test results for new:  
Non-resistor BS 491055T plug = 4.88.      Continuity - no.      External ground – no.  
Non-resistor BS 694385 plug = 8.01      Continuity -no.      External ground -no.  
Resistor OILE K6RTC plugs (3 tested) = 0.0.      Continuity – yes.      External ground -no.  
Comments, test values welcome.