"Trying to get a wire diagram for (most, if not all) MH's is a non-strarter"
I have to disagree with you on this. If a person has the mechanical apptitude and the time, it lends it self towards learning about your MH and saving the cheque book.
I fix aeroplanes for a living and have managed to find most but not all the technical data for my MH at no cost and it has saved the pocket. If I did not not have the back ground that I do then yes, I would probably have to pay the man. But I do encourage folks if able and the interest is there to perform at least some of thier own maintenace as it can help with the cost of onership.
1998 Rexhall Anthem 34' DP, Cummins ISB, Allison 5 speed, Spartan Chassis, 300 watts solar.