Thanks guys
Mike, there is room to fit the ServoCat quite easily though I probably will not.
I am installing the Nexus DSC and US Digital S6 encoders and will eventually build an aluminium framed equatorial platform....
I have looked at the Osypowski ones and like what I see.... I have lots of aluminium left over (enough to make a another slightly smaller Dob, 12" Excaliburette

)