Great!
This game really deserves to be played. Now I still have to finish Curse of Monkey Island, Escape From Monkey Island, The Pandora Directive, Overseer, the rest of Sam & Max Season 1, The Last Express, etc. before I can start Black Dahlia full on... oh, why can't I ever finish a game the first time round?
Did you play with the values some more? If you've found better settings than I posted, go ahead and share them.
P.S. Excellent, a Google search on "Black Dahlia" and "spin edges" already brings up this thread. It gave me no results when I tried searching for it.
So hopefully this helps some more people (although I fear that we are a minority in still enjoying games from 1998 like Black Dahlia
).