I'd go softer on the back, especially the damping. Increasing the side damping always seems to me to give good initial steering, but then the car doesn't straighten up on the exit, and I have to hold off the throttle until it points the way I want to go. Less side damping might give more initial steering, but hurts the rest of the turn.
If you don't have enough steering, fix that - camber, castor, T-bar, L-bar, centre spring, whatever - but simply increasing the damping doesn't work for me.
When measuring the axle width to be central to the chassis, use the stand-offs on the side of the car; those supporting the cross brace, or the body post/side damper plates on the DB12R. Place a steel rule against the post at 90deg to the chassis, then place a straight edge (or another ruler) along the edge of the wheels. Read off the dimension, repeat for the other side. This is far more accurate than trying to find the middle of the chassis, and reading from a mark on the car. HTH
