Hi Erock,
On servicing the appliances, at the top of the forum are tabs, look for the word, FILES. Click it. In there are sections that should have owners manuals and some service manuals for all of your vintage appliances.
Are you comfortable and have worked on 12 volt DC and 120 volt AC electrical? We have several here in the forum who have been through the appliances and some have done total rebuild and servicing. We can help with the tech what to look for, but it is hard to teach electrical safety if you have not been through this before. And we do not want you to get hurt. Let us know your comfort level with electrical and we can get into it in more detail oh you need help.
The soft floor, some thoughts to think through on this. Were did the water source or sources come from to create the water damage? When I go about these kind of repairs, I try to back in what went wrong before taking anything apart or totally apart. The key is to learn all you can before tearing into it. You for sure want to fix the water source so it will not damage all your good hard work.
If you can post some pics of the affected area with some descriptions we may be able to suggest some sources of water that caused the damage. Then you go and investigate. There are many ways a soft floor can happen in a camper.
This is also something to think about doing. Before you start into taking the camper apart, consider getting a moisture meter and scan the floor, walls, ceiling, the bottom plastic waterproofing material under the camper. While you can only see or feel the soft floor, water damage is very hard to see until it gets real bad and Rita through. Campers do not leak like a house. Water trapped in a wall or ceiling can be ongoing for many years before it shows up inside the lI if space. By scanning the camper you then know how much more water is really in the camper before you take it apart. And it can help guide you where the floor is wet and then becomes dry to help figure out the water infection source or sources.
See here for more on the meter and where to get at least one brand
https://www.sunlineclub.com/forums/f71/moisture-meters-for-inspecting-a-camper-17613.html
Hope this helps
John