[mill (Martin)]

Hi Mick.
I am using very dark felt opposite the focusser and in the bottom of the tube.
It makes the contrast better, you could also make all the mirror edges black with a feltpen so you won't have scattered light from the edges of the mirrors.
Last but not least, you can make up an lightschroud for the tube.
It has to be about 30-40 Cm high, this is to prevent stray light to hit the focusser because the focusser is high in the tube, i had that problem with my 10" dob.
After all these mods the view is a lot better and generally darker compared to the unmodded scope.

The felt is available from Spotlight on the canterbury road opposite Bunnings.
It is in the back, in the craft department.
I have some material here for free to make an lightschroud.