Hello,
Really thank you all for your precious comments !!!
I put some other pictures,
for the cross section ( I don't know if I have understood everything , my english is not that good !

),
it is not a diamond section, it's almost flat but a little larger in the center
looks like a large ham slicer - carpaccio knife blade
An old soldier's carpaccio maker sword ?
For the little space on the ricasso,
they used it like like that ? I saw this little space on old swords and wondered why they were made like that ( Thank's !!)
I forgot to mention the size: 70cm long for 850 grams
It seems not bad balanced, ''fits'' good in the hand
so maybe not shorted too much...