Agreed that the page in MB-C doesn't seem to show the markers going through the junction block but that doesn't make much sense to only make it easy to disconnect part of the wiring.
A reliable source shows a photo of an unmolested wiring harness removed from a known original vehicle and clearly shows wires in the main harness of the same (+/- a tiny bit) length to connect headlights and markers, all through the junction blocks.
http://canadianmilitarypattern.com/R...arness%203.JPG