You should be right Stu. The best way to check a TIP102 is to set the MM to "continuity" and then check for any shorts. Testing them this way is the easiest, and when you switch the game on, you won't have any locked on coils caused by the transistors. Measuring resistance to ground will give you different readings as you are measuring the "circuit", not the component. There are other components influencing the reading as the other components can have a 10% tolerance - like resistors for example..

cheers mate. one question re the HV section - the trimmer pot ? - do you use it? what do you trim voltages(?) to ?