A quick final assembly indicates that 0.9Kg of lead placed at the instrument panel location is enough to get the balance near the position identified on Jilles’ 3-view pdf drawing.
Thus the amount of lead secreted into the nose cone was probably about right as the pilot figure & dual battery arrangement should be pretty close.
At <12Kg it should be a floater

Hopefully we will see post paint shop & flight pics in due course.
Peter