Try both ways on your final setup. I'd use one leg of an L-pad to vary the Q and ascertain the optimum resistance value. I'm guessing the broad notch will give a good result, as the twin peaks are symmetrical. If not, consider dual narrow notches, though that's gonna be tough to get right, them being so close.

Again, my results are on HL91, not your horn. Try some polar measurements, too. See what your HF beamwidth is, maybe 10°, 20° and 30° off axis....