If you go to
COM_NET2 LINK and input your coach build number with a cs added after your build number you will get a list of parts for coach.
With the part number, could be Ford or Chev, try a salvage yard and you may get just the lens.
If you go to Newmar parts they will sell you the whole light assembly.
Welcome to irv2 and come and join us down in the
Newmar forum.