Ensure the rear wing bolt block in the fuse is glued securely.
As you have heard, Keep everything as far forward as you can.
With an OS 1.60, Mine was still 1/2" behind the rearmost cg limit.
It flew well at that though, I am loathe to add lead to any plane for balance.
The stock method for the tail wheel won't last long. Try a better (but still light) aftermarket setup.
Watch the firewall for seperation from the tri stock. The glue they use is not so good. mine was split halfway down when I discovered it after a few flights.
This plane flys very good in all attitudes, makes a good precision flyer, just keep it light or you'll have to add a pound to the nose to balance it.

Greg J