I so wish I had met Ewart Oakeshott!
I have read many of his outstanding books and am a big fan. It’s a great sword. It must have seen a lot. Pity it’s so hard to see the letters. The sequence could be something like (D)omine (N)ostri (I)esu (but ”In nomine Domini Nostri Iesu Christi” doesn’t seem to fit here).