Neshech, I never tried, but you sound convincing enough. Just hope I can find that fine grade around here.
Since we are going slightly off topic I want to do a final effort for IP to give him some (very uneducated) clues about his item.
My main focus is the size of the bottom of the ferule for a first indication. It’s (again in my humble opinion) mostly seen in heavier and larger spears, which makes sense if you imagine the force used with these things (Some were over 2.5 meters long). These spears are called landeyan (I believe) and indeed used in Java and Madura.
(Always wondered if the name could come from the dutch, langejan=Long John; no prove though
but the period seems to match).
The dapur is in my opinion common for java. The higher section in the center has the function of removing the spear more quickly after contact with its target and it will create more damage. (The broader base helps to increase the “stopping” power). There is a kind of dapur originally containing holes, but I forget the name
) Holes look a bit like made in later stage. If they were not then Java comes to mind again. As mentioned the are probably for decoration purposes, since these spears were used in (keratin) parades as well. (they still do have those parades)
Pamor doesn’t have the "madura" feel, the small lines on the side of the blade are more seen in java pieces ...it doesn’t really match from what I see from Madura.
Dating is a rough quess, but I placed it somewhere between the arrival of the Dutch and from the looks of the spear not younger then 200 yrs. Markings of numerous cleanings would have had its marks not only in the ada-ada area but on the side as well. I have no specific comment on quality, since its obvious not created for royal ceremonies. However from what I see it looks like it has been actually used (which is not really that surprising). 2 smaller cuts on the side and traces of scars in the center, so I would argue that its not well made. From the “wear” around the border, the well shaped “ferule” I would call it good quality.
There is some older drawings from actual spearfights (maybe on the web as well), could maybe give you some clues as well.
Regarding the later added hilt, I agree that its probably some mark. Maybe you can find details with the KLM (Royal Dutch Airlines), since they were the first and for long time single airmail provider in Indonesia.
General disclaimer : I’m just an amateur in this area, but I hope it has been of some help.