Thanks - that gives some improvement, but now i get:
tf@red-brick:~$ DISPLAY=:0 xrandr -q
xrandr: Failed to get size of gamma for output default
Screen 0: minimum 800 x 480, current 800 x 480, maximum 800 x 480
default connected 800x480+0+0 0mm x 0mm
800x480 66.00*
tf@red-brick:~$ DISPLAY=:0 xrandr -o right
X Error of failed request: BadMatch (invalid parameter attributes)
Major opcode of failed request: 140 (RANDR)
Minor opcode of failed request: 2 (RRSetScreenConfig)
Serial number of failed request: 14
Current serial number in output stream: 14
tf@red-brick:~$
Rob