17 isn’t one, nor is 15. I don’t think 12 can be one as it’s unclued. My 4 in the Downs all contain a thematic word in the clue and, so far as I can see, they are the only ones that do.
If you make the thematic replacement, you can use the last word all the way along. I think the 3rd word is just there to provide a letter in the answer.
ah - of course that's it - though my construction worked really well, I thought! still only 14 though - unless 12 is one, or one can interpret fine as alcohol ....