That is a very impressive smiley 
Does that rectifier contain just HT diodes or LT diodes or some combination. It does not look obvious to me from the photos of the wiring.
Once we have established what mythical properties apply to the stop end to be used in an AVO battery we need to work out what the polarity of the stop end must be and why?
There is a right and wrong way to put the stack of cells together to make the battery and a reason for it. From this you get the polarity of the stop end itself.
Another photo
Does that rectifier contain just HT diodes or LT diodes or some combination. It does not look obvious to me from the photos of the wiring.
Once we have established what mythical properties apply to the stop end to be used in an AVO battery we need to work out what the polarity of the stop end must be and why?
There is a right and wrong way to put the stack of cells together to make the battery and a reason for it. From this you get the polarity of the stop end itself.
Another photo
