This is a very unusually shaped rim (bowls sherd without an existing type). It is sort of akin to WSAC3.03.C.07 and WSAC3.03.C.10, except the top of the sherd is not flat. it is rather two part itself, that is, There is a flat axis at the top, and then a down sloping axis toward the exterior. Not sufficiently preserved to have drawn. And, as far as I can recall, it's a one of a kind form thus far.
From Interior to Exterior