She can clearly generate a personal zero-gravity field.
A lot of the “classic” old Valiant characters, including The Steel Claw and Archie the robot, actually cropped up in one of the Zenith books {Book 3, I think}, since Fleetway had the rights to them - superheroes from other publishers {probably D C Thompson} were also subtly amended to feature without violating copyright: The Cobra, previously mentioned, turned up as The Black Mamba.
Briefly, several teams of superheroes from various alternate universes were assembled in order to combat the Lloigor {Lovecraftian Elder Gods} and their minions - primarily other old British superheroes whom they had possessed - and thwart their plans to achieve universal domination. Thus a lot of the old Lion and Valiant characters, together with 2000 AD’s newer creations, got to battle it out: they won, no thanks to Zenith’s shirking, but sorry, but The Steel Claw didn’t make it.
More Zenith backstory available on request…
Oh, and Tim Kelly and his amulet also later turned up in the not-very-good Universal Soldier series in 2000 AD {no relation to the not-very-good movie of the same name}.
I’m also remembering New Statesmen from the shortlived Crisis comic, Fleetway’s failed late 80’s attempt to create a more “adult” comic to capitalise on the success of 2000 AD and the perceived increasing maturity of the comics market. From what I can recall, the series was set in the near future, when England had become the 51st state of the US: each state had its own representative superhero, so there was an English one - I never really read this comic, I can’t even recall the writer {John Smith? Grant Morrison?}; the artist was Jim Baikie.
Nemesis was a Warlock, an alien demon {see my earlier post for more details}: from memory his home planet was Gandarva, although he never spent much time there, being too busy saving the universe.
Could you elaborate? I asked because for a moment I read the thread title as “British superheros with british superpowers” which had me wondering what sort of superpowers were british. 
What about Captain Scarlet?
Well, how about the ability to say complete sentences using only two vowels in the entire sentence!?
British superpowers would be astonishing queueing abilities and the ability to eat curry sober.
Another, sort of, superpower types were the Tommorrow People who could teleport themselves (I was quite scared of them)
Captain Scarlet is indestructable. You are not.
HURRAH ! BRITISH SUPERHEROES ! !
etc. etc.
Atomicman
Captain Universe
Electroman
Masterman
Streamline
The Tornado
Wonderman
The Doctor is only mentioned once in passing?
Though the Doctor was born on Galifrey, he has spent considerable time in the UK. All of his regenerations have had British accents. He is a skilled cricket player.
Superpowers?
If not killed by violence, or disease etc he has a lifespan of several centuries.
After dying, he will regenerate into a new individual with all the memories of his old selves. Most Timelords can do this IIRC 13 times. There are hints that the Doctor will find a way to exceed this limit and have as many as 40 regenerations.
The Doctor has a temporal sense. Among other things, this alerts him to tamperings with time/space or alterations of the timeline.
Several regenerations have shown hypnotic abilities.
The Doctor has also had- a flying car, 2 robot dogs, and a sonic screwdriver.
Add to that the revelation (in Battlefield) that at some point in his future, the Doctor will go back in time and aid a certain king while using the alias Merlin, and I’d say he’s a British superhero
RE Bucky
OTTOMH Bucky Barnes was an American.
Re Excalibur
They sometimes teamed with the shrinking hero Micromax, who was an MI5 agent.