First, congrats on your purchase, and welcome to IRV2!
Re: the manuals, I'll be surprised if you find much, and even more if you found what you're after and it included any info you were after. The user manuals are generally pretty generic. If you have specific questions, fire away. Answers/ideas you get are the house specialty!
Re: the fender, have you tried a Holiday Rambler dealer? If you can locate one that's been around a while, wouldn't surprise me a bit if they could come up with one.
Best of luck!
1997 37' HR Endeavor, 275hp Cat, Freightliner
03 CR-V Blue Ox, Ready Brake