Hi Hoa, Mr Randy Osborne in San Jose, CA, could hlp you to find some of music pieces which David Moreno played.
Myself, knowing that David only played musics of other composers, and he himself did not compose any piece, also he did not write down nor publish his transcriptions of the pieces he played !
Randy is vey knowledgeable about D Moreno ( and other guitarists ), you could contach him by his email :
and here is his website :
Good luck !