As a reporter, I did two TV stories with Glyn on his original rebuild.
Not sure about the sourcing of the wood, but he told me some of the production of the Mosquito was outsourced to English furniture factories during the war.
He said they had to work to watchmaking tolerances in wood.
Lofting of complex curves and radii - all done by hand on paper - he said recreating it from the DH documents he was able to get copies of was an enormous task.
Concrete moulds were used to cast the steamed plywood/balsa sandwich fuselage halves, which were then glued together and covered in doped canvas.
I remember being struck by how thin the fuselage cross section was where it joined the empennage.
Beautiful aircraft.