Have you contacted
NuWa?
They might have an old one laying about.
That being said, most manufacturers "manuals" are generic and not worth much. All the usually have is generic RV information. Nothing on say where the wires or plumbing is.
Also nothing on the sub-systems, ie water-heater, furnace, refer, etc.
To get those you need to go the that sub-systems web-site and see if they have a PDF for that model.
Yet another option is the RV Repair and Maintenance Manual by Bob Livingston. Actually that book is a good idea anyway.
2008 F350SD V10 with an 2012 Arctic Fox 29-5E
When someone tells you to buy the same rig they own, listen, they might be right. When they tell you to buy a different rig then they own, really pay attention, they probably know something you don't.