In the beginning the Numbami inhabited the 'inside' (leeward) of Awayagi Island (toward Morobe) and Ulingi Point (across the present cove from Awayagi toward Kuwi). All Sibomas will cite these as their asples ['seat-place' = homeland]. Whe they were living there is not clear. It is not within the living memory of any Siboma and preceded time of contact with records-keeping Europeans. I estimate 1850 or so.
At this time they were in the path of raiders from Morobe in the south and Lababia in the north. The Siboma court against Paiawa hinged on testimony from Morobe that Siboma were who they ran into when they came north. Paiawa at that time were 'man bilong bus' [inlanders] and did not live on the sea. Even now the [non-Austronesian] Paiawa are regarded as close relatives (thru intermarriage) but rather of the country-cousin variety. To the north the Kela were at Lababia though they apparently traded widely and that place was the site of a (yearly?) pig festival, called bada by Siboma & possibled related to their verb -bada 'to distibute', and called a sam by I don't know who [Jabêm-speakers]. Sam is what the yearly church meeting to be held in Kela this September is called.
To escape the raids the Numbami moved up in the hills above Karsimbo River and apparently were as mixed up with the Bapi people, all mountain people, as they are with the Paiawa now. Probably moreso; the 'two' groups were described as being really one by S., and the old kaunsil, who must have been born about the turn of the century or about a little before contact, says he is really a Bapi man. Since they had to have some time to get this mixed up with the Bapi (non-Austronesians like the Paiawa) they must have left Ulingi and Awayagi around 1850. When some Europeans came to this village, called Yawale, the Bapi refused to carry for them and apparently were massacred in retaliation. They fled farther up into the mountains (they now live on the Waria River) and the Sibomas came down to Karsimbo where they were living at the time the mission contacted them and (presumably) named their harbor Braunschweig Harbor. Karsimbo is a good defensible, deep-bayed place.
Apparently due to mission influence or maybe just the cessation of fighting they moved to their present location at the Sayama River (or creek really) in the shallow harbor situated between their old Ulingi Point and Awayagi Island. Apparently these old villages were abandoned so long ago that the old tall coconut trees have fallen down or broken. Now only young trees show where the old villages used to be. Karsimbo is still marked by tall old trees and still has a habitable shoreline whereas Ulingi (and probably Awayagi as well) have lost theirs.
The story with the Buso [up the coast toward Lae] and Kuwi (which also probly matches the court record) is apparently that at some time in the past a dysentery epidemic hit Lababia and everyone fled to their kinsmen all over the Huon Gulf (which may speak for how widely they traded since trade was mostly between kin). A Siboma man asked the Sibomas if he could settle some of his kinsmen at Kuwi (Ya to the Sibomas). Another group apparently established themselves at Buso (two coves up toward Lababia) independently at around that time. Well, later the Kela and allies--mainly, I take it, Kuwi, Buso and Lababia (all Kela wantoks [speakers of the same language])--planned a great raid on the Sibomas living at either Karsimbo or Yawale. They snuck up, surrounded the village during the nite and, at dawn, attacked the unprepared Numbami, reducing their number considerably. A while later the Siboma undertook a similar counterattack against Buso (or Kuwi?) and only desisted from slaughtering them all because they had a relative in the bunch. So, according to S., they killed one Buso for every Siboma dead in the darlier attack and called it even. Whether good sense or colonial rule put an end to that feud I don't know but it seems to have ended there.
The [Austronesian] Kaiwa were perhaps earlier pushed back by the Kelas and now considerable bitterness and fighting mars the relations between the two language groups. But S. thinks the Kaiwa, like the Paiawa, were earlier man bilong antap long bus ['people from up in the bush'] and that it was only with Kela evangelizing that they came to the coast.
A final point: the money paid by South Pac. Timber to the Sibomas was split 3 ways among the Paiawa, Bapi and Siboma--I think on a 3:3:4 (or 2:2:6?) basis.
P.S. No one knows how and why the name Siboma came to be applied to the Numbami.
SOURCES: Sawangga Aliau, kaunsil, and 'Abu Bamo' ['grandfather big'], former kaunsil, both of whom were involved in successful land claim court cases involving Siboma claims against Paiawa on the one hand and Kuwi (and Buso?) on the other.