A word for “potter” in The Etymologies of the 1930s under the root ᴹ√TAN “make, fashion” (Ety/TAN). The root ᴹ√KEM “soil, earth” instead had ᴹQ. kemnaro “potter”, with a line drawn from it to the forms ᴹQ. kentano and N. cennan in the margin, but both these marginal forms were deleted (EtyAC/KEM).
Neo-Quenya: For purposes of Neo-Quenya, I prefer ᴹQ. kemnaro “potter”, but if you wish to use kentano, you should update it to ᴺQ. centamo, since ᴹQ. tano > Q. tamo in Tolkien’s later writings; see those entries for details.
A word for “potter” in The Etymologies of the 1930s under the root ᴹ√KEM “soil, earth”, apparently an agental formation based on ᴹQ. kemna “of earth, earthen” (Ety/KEM). It was first written as ᴹQ. {kemenāro}, and there was a line drawn from kemnaro to forms ᴹQ. kentano and N. cennan in the margin, but both these marginal forms were deleted (EtyAC/KEM).
Conceptual Development: The Qenya Lexicon of the 1910s had ᴱQ. keresto “potter” based on ᴱQ. keres “earthenware” under the early root ᴱ√KERE “turn” (QL/46).