G'day John.
"Looking at the bike I am puzzled as to why they needed to make the pillion loop from 3-4 different pieces welded together "
Yes it looks like they used a mandrel bend off the shelf and welded two straight sections to it. Should have inserted a sleeve, V'd the ends, welded and then ground flush.
With all that electrickals EFI, ABS, USB's, etc it's a good job Lucas wasn't used.
Cheers