As best I know, the 1st Alpine rolled off the line as a 1998 model. I know nothing about Alpenlites.
Regardless, RV manufacturers buy the equipment that build their products with and I believe you'd be better off placing the inquiries with manufacturer of the Water Heater. The OEM/MRO parts would have to come from them in any event.
Bob (Squidly Down Under) & Peg - 2013 Ford Focus pushing a 2011 Phoenix Cruiser 2552S
"In God we trust" to preserve our country and bring our Troops safely home.
Carry on, regardless..................