Casey Jones?
I remember them being at Stansted airport but can't remember them at stations. I'm guessing they were replaced by Burger King in much the same way that Wimpy was in the high street.
If memory serves, the general rule with Casey Jones burgers was that you knew if you were drunk, because you'd buy one, and you knew if you were REALLY drunk because it would taste nice.
But were they better than Julies Pantry at the motorway services? I remember stopping on the M4, and buying the greasiest, fattiest burger and chips I can remember. I was very hungry and reluctantly ate it.