Ah... yes, you are right Alan, I stand corrected... sadak is the rolled betel leave, and (was said) used by Jaka Tingkir to kill Dadung Awuk. And I also understand that words do not always mean what they might appear to mean, as the duel with Dadung Awok mentioned could just be a metaphor of what jaka Tingkir had done to warrant a punishment (stripped of his position and outcast).
And you are also right about gobek
back to the topic, IMPO, keris of pusoko standard among wong ndeso does not really care about aesthetic, compatibility blade to wrongko or ukiran. As Mrwizard pointed out earlier, the hilt struck very close resemblance to tau-tau statue of Toraja, i think the blade and hilt originated in Sulawesi.
Though Toraja people are not keris bearers, some of their pusakas are actually keris, made in South Sulawesi (ref: Kris Disk by Karsten Sejr Jensen)