The sets I have used have all had a two wire section mid way along the set. Divide the set there and unless there is a CPC as well you could use a smaller 2 pin connector
Mine has 3 wires in the middle.
It's actually made up of 4 40x6v lamp sets in parallel.
No cpc.
But I agree - trying to draw it out it doesn't make sense that there would be any more than 2 wires in the sections between lamp #40 & #41, #80 & 81 etc.
I need to get them down before xmas as I want to check if some spare lamps I bought are the right type, so I'll have another look.