If you can find a number on one of the lenses that remain, I suggest going a search on Amazon as well as contacting RV parts outlet, it is quite possible that you can get a lens. I have found obscure lenses from both sources in the past. eBay as well.
History: '08 View, '05 Chinook, '01 Jamboree 24D, '78 Apache Popup, 81 Komfort Tlr,
84 Mazda B2000 'w canopy,
Tent from wedding shower in '96