Unless you are lucky enough to find another 2001 Dolphin owner and a photocopier, you may be out of luck unfortunately. My Class A is older than yours, but I've had the same problem with my Thor. The company is still in business and owns several other RV manufacturers now, but they don't make the Residency or any "Thor" motorhomes anymore. From calling around to a bunch of different places that supply older RV parts, I finally got the number to "a guy" who did have some Thor motorhome paperwork on file. He faxed me what he had, which was minimal but at least something. Perhaps there is someone out there with the same collection of National/Dolphin documents.
You could look online at various classifieds sites (eBay, rvtrader.com, rvtraderonline.com, and many more) and find a rig like yours... then contact the seller and ask (1) if they have the paperwork you are seeking, and (2) if you could pay them for their time and inconvenience to copy the materials and send them to you.