If the question of laminated - or not - sides and back in the Paco Castillo guitar model 204 is still unclear, let me humbly turn your attention to my post from 30 November 2017 in this thread. The reason is that I quote there information from Mr. Luis Julia who is one of the owners of the Paco Castillo brand (and one of sons of Master Jaime Julia Abad - the founder (with his sons) of the Paco Castillo brand - the key figure in this story)
we shall also find there short info on Mr. Luis Julia:
...Luis Julia was Alhambra’s engineer from 2004 – 2009 and, apart from directing and controlling the production process, he designed all the n
ew models of guitars launched by the Company since 2002, such as ‘Crossover’ series, the professional line, the 8Fp, 4F, Requintos CW, Antifeedback etc,
He also collaborated with the Universidad Politécnica de Valencia (Valencia Technical University) and the Universidade do Porto (Porto University of Portugal) in investigative projects Which resulted in improvements in a series of guitar models. He was also the driving force and computer programmer behind the introduction of numerical control machines...
In case of any doubt every interested person is also kindly suggested to contact Paco Castillo - the email adress is at their web pages.
With my best
Jacek A. Rochacki
Antonio Picado, model 60, 2015, Cedar/IRW. Scale 640 mm.