That sport wagon photo gets passed around from time to time. I'm not sure they ever built one. I did see one century wagon with the slope back nose, not the normal century sedan nose listed up in Alberta a few years back, but it didn't have the hood or that paint.
Was this Century wagon built?
I recently picked up some automotive stuff from a former Delco employee. Among them was some literature. The picture below of the 1978 Century sport wagon is interesting as I have never seen that paint job. A little hard to tell from the picture... is that burgundy paint or fake wood grain? Notic...forums.aaca.org
However if I ever do repaint my wagon it will get that sport wagon scheme.
I'm torn between really liking that idea or saying keep the woodgrain, both good looks but since so many remove the woodgrain, or it just fades/peels off, I generally support keeping a woody a woody.
Awhile back I went deep into the interweb and down the rabbit hole looking up the sport wagon and could only find one other pic, this one was used in a movie so who knows where it came from, dealer promo or factory leftover they let a studio use(?) but it matches that brochure picture. And also found a thread on a Buick forum talking about these, some links to 79' brochures showing more info. Seems they were available and made but I'd guess pretty few ever were made.