A great thanks to all who replied and added further info. I must admit that I never thought about looking for structure WITHIN the Horsehead, so here is an additional challenge for me. I hope I will have another chance to go after it with my 18" before it's too late, we have had 188% of normal rainfall this winter in my vicinity with all the murkiness this translates to...

On another note, last Saturday evening on a so-so night, we (with NicosCY) were able to detect IC434 as a faint stream of nebulosity at a quite low power using Nicos' 50mm refractor, the TV Panoptic 19mm and a H-beta, but we were unable to confirm the existence of B33. This will probably take a better night...