Hand router. This one looks to be a home-made copy of the Stanley 71 1/2. Ebay has one, item 190571243842
I have one, and have used it for years now. Good tool. I think the knobs on the Stanley are more useful than
the handles on the one you found, and the raising and lowering feature makes things easier than the set screw
adjustment on yours.
I only use "old woman's tooth" for the wood stocked routers, often made from sections of stair rail. I've seen wood
stocked examples that follow the general pattern of the Stanley version.