Im not 100% sure but i think on the PE forum we might have CAD drawings of the N battery box. I know we got the T/X one done. It will then be a simple matter taking it to a sheet metal specialist. If we havent got the N battery holder drawn in CAD then we can look at getting it done. The N battery holders are really hard to find as not all states got blinkers until 1980. I would have to dig through some parts books to confirm but i think its the same part number as the 82-84 PE175 battery holder.
The DG heads are not impossible to find, there has been maybe 4 or 5 on ebay in the past 3 years.