I finally tried making my own wiring harness for my 340U, using asphalt impregnated loom from Brillman. Actually making it wasn't too bad, once I learned a few tricks from the guys over at YTMAG. Be glad to pass them along if anyone is interested. I'll do all of the terminations to the dash first, and then once the harness is in place I can trim the wires to final fit and then terminate them.
Then I have to do the Cub.