Mel,
I see you also have the SM60II DS...
You've probably already used the radial positioning and variable tilt to reduce ghosting.....
In the Lunt DS I believe there's limited opportunity to have any "tilt" adjustment. A CP filter in the optical path may reduce them....
I don't have a Lunt to experiment with, so can't add much more.
There are many guys over on the SolarChat group who have Lunt experience which may be more useful.
https://solarchatforum.com/