Hi.
For what it's worth....
Here's the 'Pianist styles' that is on G-70.
Two folders, one 'first edition' and the other form the v3 edition.
As I remember it, they tuned the styleset to OS v3 update.
Also added the few ones fron BK-9.
If I find any more, I'll add later.
Hope it's for any help, if not, Diki can delete my post.

Btw,
if it's any interest, I can convert the 36 Yamaha pianist styles from PSR9KPro.
I think that's the files who will give best result if convert to Roland, also best as starter to edit and tweak.