This has been incrediably entertaining. First to the OP. Put the two theories together. Jackamo does mean clown. That's how my Creole Mother used it. It can either be used as a noun or a verb, as in you clown or to clown around (all out foolishness). Finane means "It is finished". Jacomo Finane means literally, "Your clowning is over". The song Iko, Iko tells about two Indian tribes meeting. One Flag boy threatens to burn the others flag which would equal wiping his gang out. The other says, "Here comes my Chief, your foolishness is over". That's it, nothing more, finane.
One other thing, Nainain and Parain (pronounced Na nan or nanna and Pa ran) are Godmother and Godfather, not Grandmother and Grandfather.