That looks really really good Al.
What did you use for the "Household" rusting solution? I'm thinking, hydrochloric or toilet bowl cleaner (Phosphoric based)?
Actually the solution is just a medium to speed up the process. You can achieve a real rust blue by just letting the parts rust....takes weeks.
Play with the PH of your boil water (use distilled) by adding a drop at a time of muriatic acid. You can move the colour from the warm plum black that you have to a coal black and on to deep magnetite.
If the colour suddenly fades during a boil you've gone a bit to far down with the PH, add water to bring it back up
Which commercial solution are you going with?