The welding is about to start on the odds and ends of rust and the damaged / butchered parts of the van. The ugly gash will be welded up, but what about the round hole next to it? It looks OEM because the edges are neatly swaged over, but is it really, and what is it for? One on each side, 1972 cross dresser.
I've never seen the fog light wiring in there but that does make for a neat job. As mentioned they do make for handy waxoyl access points especially the O/S one. There is a drain hole on the battery tray that goes into it hence why that rear valance rots out. It's also a good visual sign if there has been any work on on the rear end.
Look like production cradle spigot points to me. Mine has a 10mm tapped pad on the outboard face of each chassis rail, suggesting a locking bolt to engage with the spigot once its in place.
Ahhh thats what these holes are for...I thought they was for routing towbar wiring through (or sticking your finger in)