There are several ways this problem could be approached. The one selecte
d really depends on the faceter.
If I were recutting the stone, I’d select the cut I wanted 1st, then dop
based on the cutting sequence. However, since you’re starting with an
already cut round stone, I’d do as you mentioned. Dopr the pavilion of th
e existing stone & cut the crown of the new stone 1st. Dopping the
pavilion in a cone dop would keep the centerline of the 2 stones pretty much
inline. Long & Steele have several good hex shaped Barion cuts in their
Barions book. The depths run from 75-85% of the width.