Yes, sounds like the 'Phantom' - I bought one in 1979 from Pindisports in Holborn, London, and it knocks spots off that ridiculous shapeless Terra Nova Laser that I got from Ebay - apart from the weight of course.
I was using my Phantom this July 2013 on a quick drive round northern Norway - one of us slept in the car on mattress, quilt & pillow, the other slept outside in the Phantom (2 guys you see!).
Once I timed the set-up: 7 minutes.
My Phantom has been used in the Pennines, Lake District, Germany, Netherlands, Finland - 34 years old and still looks good. 79 Pounds (GBP) it cost.
I was using my Phantom 2 weeks ago in northern Norway, I still think it's a good design. Threading those rods through tents like the Akto is a right pain, although of course the Akto is 1.3kg and the Phantom (2-man) 3.5kg or so...
You say: "I BOUGHT THIS ON A WHIM" and then "I HAVE NEVER ACTUALLY ERECTED IT" and then - "IT LOOKS LIKE IT HAS HARDLY EVER BEEN USED, IF EVER" - why would it have been used as you say you bought it and have never actually erected it? I mean, surely you would know it HASN'T been used ???!!!
Yes, I tried the links and they just go to the front page. Try www.crazyguyonabike.com then search journals 'From Wychbold to Skipton', 'From Wychbold to Darlington', 'From Wychbold to Drammen'. (and you'll find them in the locales England & Denmark)
If anyone's interested in a cycle tour (included a lot of walking up the hills!) of one of the nicest parts of the world, you might be interested to have a look at my latest 'journal' on crazyguyonabike.com