Based on his
twitter post I think Yasuhisa Ito only did 5 (it reads like "this is the song I did")
Also, Tomoaki Hirono
says he did 3, 4, 8 and 18, seems only that (new songs).
Thus that'd imply the other new songs (1, 2, 17, 19, 40) are by Yasuhiro Ichihashi.
(however, I wonder if 2 isn't Hirono's, since his titles are all in CAPS)
Hooray for the twitter generation.