Dear Nechesh,
museums in Europe have started from the 14th century and even before. Of course, and unfortunately, inventories don't come back to that date and more over regarding keris.
nevertheless and since we talk of Durga hulus there are two of them, one from the General Wrangler Samling collection (first traced) in 1676 (p 87 of Den Indonenesiske kris of Seir Jensen) the second and more known, Durga hilt made of rhinoceros horn and decorated with gold and rubies (first traced 1618; Der Deutsche Orden in Vienna) (One of the first inventories that we know with out doubt so far).
So you are absolutely right, you say no one can confirm it is from 14th century. At least I can say it is at least from 14th (ref Candi Suku) to end of 16th. I even can bet on it
for the second aspect here are the pictures.
the wooden one is also used and slightly damage on the hand. I suppose it is due to a hurting of a stronger material, but it can also be the wear of the thumb
The ivory one is obviously much later 19th or early 20th c, I would say and cannot be compared.
I’ll try to scan the pictures of the book to show the Durgas from Sier’s book I’m talking about.