I really think that the question now is should YOU carry on HD? [post 56]. Not "we" ie David.... who has probably gone for lie down after all his efforts. You don't seem very happy in your task or with the radio itself now. It's not very difficult to answer most of these questions yourself, especially if it's just identifying a component like a rectifier
The normal process is doing some work and asking questions only when really stuck. Unfortunately you seem to have been stuck with nearly everything so far,
-and repeatedly-is this hobby really for you
Dave W