All Alberto does is to get the basic shape by heat moulding. The final shapes
and contours are got by hand, by means of carving and sanding.
Note, if it isn't obvious, that the top wing tapes to the underside of the "shelf", and does not rest thereon.
Using this fixture, you can eliminate all the screaming, swearing, and hair-tearing associated with top wing attachment. As I mentioned in the article on the W.12, I now routinely set the wings on the model as soon as a fuselage is available, using white glue. I check strut fit and placement, and get some practice in the best angle of attack for that particular plane's struts. Then I take the whole thing back apart, clean off the white glue, and proceed with detailing and painting, knowing the permanent attachment is easily accomplished.