This is a guess of an ignorant person. I think, for somebody, who has been in a forge in Madura this must be an absolutely clear case.
To me wrongko seems to be real pelet wood, if it is old, it's overcleaned. This and the same for hilt reminds me of an indonesian "restoration". The sheath mouth could be recently wided for the blade.
The blade could be reworked old material (?).
Take with a box of salt
