My apologies for not having better information. It is rather scant.
As far as I can tell, the guitar top is solid spruce or Oregon pine. The back and sides are Brazilian rosewood (jacarandà, is that right?). I believe they are solid wood as well. Some posters online say the fingerboard is rosewood too.
The book matching of the back pieces suggests the wood is solid. The back, it appears, is arched. The best site on Di Giorgio's I've come across belongs to Marco Bessone.
He describes a Estudante No. 28 as follows:
"This instrument has classical shape and dimension and owns a good quality sound. It's ideal for beginner guitar players. The resonance chamber is made of Pau-Ferro and the harmonic board is made of Oregon Pine. The frets are in alpaca and the machine head is in steel."My 1974 Classico No. 28 may differ as they are different model years and, apparently, the quality of the lower-end Di Giorgios declined over between the 70s to the present.
Bessone also describes Di Giorgios which he personally owns. He too has a Classico No. 28 but it is from the 1960s.
The lower bout (lower width in Martin parlance) is 36.7 cm at its widest. Its depth (outside edge) is 11 cm. Scale length is 64 cm.
