I used to own a plate for making dowels that made fluted dowels instead
of smooth dowels. I have not seen it offered anywhere and cannot
remember where I purchased it before. Unlike the Lie-Nielsen Dowel
Sizing Plate which makes smooth round dowels, the plate I am thinking of
would cut flutes as the wood was pounded through the plate.

Does anyone know where a plate for making various sized fluted dowels is
offered for sale?

John