That works.
Just needed to change the 1b size profile to:
<Fixture menuname="Test moodlight 8x8 1b" uniqueid="MOO2" excelexportid="MOO2" pixelwidth="8" pixelheight="8" output="RGB" channelcount="192" orientation="BOTTOMLEFT"/>
Seems to be doing what it should now on the tile.
Thanks Richard
Cheers
Toby