The closest I could find was this on the 2008 Sandpiper. They have a tab for Brochures which will give you basic information.
For manuals, you need to get the make and model of your appliances and go to the manufacturers website to download manuals.
The original owner probably got the information at time of purchase and discarded them.
However, don't get discouraged. Most of these appliances are used on different models and some things are pretty standard across the rv industry.
So if you've got questions, please ask.