Have flown on both the Yukon and the Cosmo. The only trip I took on the Yukon (back in 1966 at the tender age of ten) was coming back from Metz to Trenton, and the seats were facing forward. Same for the Cosmo.
HOWEVER, there is one aircraft type in which I DO remember the seats facing backwards. I flew on them several times (as a dependant) from Sardinia, to Metz, and Zweibrucken. The thing was called a Bristol Freighter; a truly amazing aircraft that looked like it should never have flown at all. It had bulbous clam-shell doors in the nose, with the cockpit sitting above and just behind them as though it was an afterthought --("Look old boy, we forgot the seats for the damn pilots! Oh well; just stick them in a little blister up here and that will do."). It had a fixed undercarriage, two radial engines, and a conventional tail. The standard joke between my folks was that we could walk to France faster, (the thing was even slower than a Dakota).
I heard a story (likely apocryphal) about a Bristol Freighter joining the circuit at some European US airbase in the 60s. As he entered the downwind leg, the tower--not having any idea what an arcane beastie they were dealing with--gave him the standard "Check gear down and locked...". The bemused Canadian pilot replied, "Roger; gear down and welded."
If you've ever been to Yellowknife you'll likely have seen a Bristol Freighter. There's one mounted on a rock outcrop just outside the airport. Max Ward bought it from the RCAF when the thing was retired, and flew it up there for several years. Don't know how many of them he bought altogether though.