Nice Trillium!
Though I suspect it is not a 1978. I am sure it is registered as such, probably was
sold in 1978, but there are some details that say 1977. I am splitting hairs of course.
The details I refer to are:
The window in the door doesn't open.
The kitchen doesn't stick out to accommodate a larger
fridge.
The fabric of the cushions is in the 1977 style.
If you like, compare your serial number to this list:
http://www.fiberglassrv.com/forums/f...tml#post521768