Discussion about the Korg PolySix synthesizer

After replacing the NiCD battery with a Lithium in my Polysix, I'd
like to do the same with my Korg Trident MKII and Kawai SX-210.

On the Trident schematics, the battery circuit looks just the same as
on the Polysix, so I guess the exact same procedure should be
applied -
cutting out the capacitor marked C27 and replacing R29 with a 1N4148
diode (what I used on the P6), so the 1N4148 cathode facing the anode
of C27 and the cathode of D15. Can anyone confirm that ?

And what should be done on the SX210 in order to convert to Lithium ?

The diagrams of the battery section on both synth are here:
http://photos.walla.co.il/gilwein

click the link for "schematics" 

Thanks !