Try again. It was just the number that was wrong. FP  *31* is shown crossing the boundary between railway and field to join FP 25.  I suspect that FP 25 has been allowed to "decay" (it is still on the definitive map). FP 32 does follow the line of the old railway - I think this wagonway is sufficiently old that it has long become an FP. *If* there is no stile  / fence crossing for FP 31 (which would be worth mapping), I suggest leaving as is.