Sunray, my ignored letters make no sense. The across ones are B, R, A. The down omissions are T, D, N, N, I, E, L, R, R, S, E and N. I can’t parse 14a, 28a or 46/47a so there may be another letter in one of them
Nelson, I too have those three groups. Why do you think 21d is involved in the fourth group?