Just recently got this rod in 7/8 class. The name does give a hint of what it is designed for, but I would appreciate experiences and views on what this rod works particularly well for and what type of use others have had it for.
Also tips and recommendations on lines that works well on this would be much appreciated. I have it coupled with a Hardy Sunbeam 8/9.

Oddly the finish on the rod is matte. All pictures of these I´ve seen are normal glossy finish.

Thanks Scotto, no, it´s a fixed butt I think, but now when you brought it up, I have to check the butt again if it is actually a model that I could get the extension to.
Still snow and ice everywhere here, so I must wait long into the spring before I get to try it out.
The rod itself is in great condition, besides that it looks like some previous owner has coated the rod with matte varnish. Just close to the handle I can see a glossy finish on it. I´m thinking of doing a reverse coating back to gloss, but not sure how to do it without damaging it.

I had one and, as other posters have commented, it was very much for fishing the big English reservoirs, especially from the bank.
Where Hardy had a dual line rating, that was always intended to indicate the double taper rating (lower figure) vs what was then called "shooting taper", but would now be weight forward.

It was a good rod, but I never got as much use out of it as my Hardy Invincible: a 6/7-weight 10ft 6" rod that was a real jack of all trades: rivers (sea-run browns, summer salmon), stillwaters (both from the banks and drifting in boats). and saltwater (sea-run browns, again). The Invincible was a pretty soft action - the Superlite always felt remarkably short and stiff, by comparison.

As far as I can recall (and I spent a LOT of time in the Pall Mall shop as a kid!), none of the "named" Fibalite rods (Invincible, Superlite, Little Lake) had the normal Hardy detachable butt extension, just a slightly cheap plastic combined butt cap and uplocking screw thread.

Yes, they do make removable butt for these. Here’s mine. It enables the rod to be fished more like a switch rod. I find a Hardy St. Aidan to pair about right for me but then I’m wanting something to balance the rod more for two handed casting. I think a Marquis 7 would be too small for this rod. I’d go with the 8/9 Marquis, St. Aidan or a Zenith. Just my two cents.