The Cravens obviously had standard B'n'T for most of their lives, and probably all of their lives in a few examples.
Rather than the "tippex" livery, they received a specific livery which no oth vehicles carried, in IE times, with the first being repainted this probably about 1990 or so. This leafy the basic B'n'T the same, but instead of the broad white line above the windows, a thinner one plus an orange one were substituted. Only one or two ever got a white line below the windows too, and they didn't retain it long. Similarly, one at least, and possibly two, got the "set-of-points" logo at each end, again for a temporary period.