Manuals for common appliances such as suburban or dometic manufactured fridge a/c furnace hot water heater etc can be found to download on the web. also the Onan generator manual
the original R/T used to have some documents ( mostly sales brochures) available online. these described the usual features on the van and some locations of components
For mechanical "chevy stuff" check your underhood VIN plate, it is likely a 2006 model which may be of import if getting mechanical parts