Congratulations on new toy. Sure playing in 104F heat is fun :D
My Fleetwood is orphan as well, but camper parts are pretty universal, so the only problem I had was finding replacement for bathroom cabinet latch.
The cable routing on campers for some strange reason come from 5th wheel setups.
On my Fleetwood I do have trailer cable extension, so from front electrical box on pickup, the 12V power and camper lights wires go 18 feet to the rear plug, then 12' of cable to junction on front of the camper, than internal, about 14' long loop takes the power around the camper to electrical box on rear right side.
That is like 45 feet of wire to carry power between boxes that are 12 feet apart.