Nydam-Kragehul spatha from Nydam.

[Damianus Albus]

but if you rest the pommel against the palm of your hand (like a handshake)

Aaaaaand this is were 10-11 cm grips come in the picture.

Aaaaand tell me how you want to use 9cm handle? since you need to cut the bottom of the pin and hammer it again so it loses 10-15mm, when changing the the grip, so from 15cm I will have 12-13cm which is all right for but I hardly can imagine getting to 9,5cm from 11cm. Could you use 9,5cm grip? I don't think so.