The Thames 2, Granada 2, and LW2 logos look realistic, but I really can't see ATV2 or Yorkshire 2's looking like that.
The Granada one looks familiar, didn't they use it, without the 1, for their. 21st anniversary?
The ATV one is quite clever but I don't think they ever have come up with it. How realistically they'd be used would depend on how good an ident they would make. They're all good but they were designed as logos, I don't think most would be feasible on air