Here is one source for genuine Norcold door panels, but I would just get a local shop to make them. They are just inserts that slip in. If you want black lexan, most any glass shop could curt and fit them. If you want wood, a cabinet shop could do it. Or most any amateur wood worker could probably do either one - I've made some myself.
Door Panels for Norcold72-4850 - PPL Motor Homes
2004 American Tradition; 2014 Buick LaCRosse
Homebase in the Ocala Nat'l Forest near Ocala, FL