Buz:
Here's the problem: There is not, and there has never been, any requirement for manufacturers to keep info for older models on file. Info like wiring diagrammes, spec sheets, materials lists, just plain isn't out there, in most cases. What you're looking for probably went into a Dumpster, years ago.
What you have to do with a mobile home is to be self-reliant. For instance, if you need to know more about what wiring you have, you need to trace it yourself, or have an electrician do it.
www.mobilehomerepair.com is a group where you can ask questions about older units; my experience on that group is that somebody usually has had a similar issue, and can advise you.
On your wiring, you MAY (or may not) have aluminium wiring, because of the vintage of the unit. I would urge you to get an electrician in to check the unit's wiring. Aluminium wiring is susceptible to problems, because it heats up when it is used. The heat is not that much, but when it heats and cools as you turn stuff off and on, it makes the connections in the wiring work loose. That can create a situation where the wiring sparks. So, find out if you have aluminium wiring, and if you do, have the electrician tighten all connections.
Sorry to be the one to tell you, but there is no instruction manual for older units. You have to learn it all for yourself, one question at a time.