While being at programming the SAM2795 I see on page 31 of the manual "MT-32 sound variation #127".
Send CTRL-0, then PC
0 - controller 0 value ( zero for General MIDI capital sounds)
I wonder if the sounds in this bank are different and worth exploring, or if it is just another mapping.
So I would like to give it a try.
I'd then send:
7f C0 41
for 65 Acoustic Bass
(EDIT: corrected term "page" into "bank")