You beat me to it. That page has almost everything on the "ring ship". It's worth noting that photos or paintings of the ship appeared in "Enterprise": in the pilots' bar in the episode involving earlier NX ships, and in Starfleet HQ after the Xindi mission and time Nazis. So that ship actually did exist in the ENT continuity, sometime prior to the 2140s.
My take is that it was a separate warp-reseach project, trying to replicate Vulcan-style torroidal nacelles instead of further developing Cochrane's cylindrical design.
Also take a look at:
That's a page from the 1980 Star Trek Spaceflight Chronology, which is where the liner concept comes from. Rick Sternbach designed the ships in that book, and you'll note that his liner differs in some details (esp. the "bubble" look of the needle-hull). The SFC uses a different timescale than that later developed by the Okudas and others, and in that timeline the liner was built in the years following the Romulan War, so in adjusted dates it would be a late-22nd century/early 23rd design. Keeping those differences in mind, there's room for both versions to exist.