"Westron nowhere appears in the book (save a couple of "actual" hobbit-names presented in App F”? Tolkien first mentions Westron in his Prologue where he writes:
And in those days also they forgot whatever languages they had used before, and spoke ever after the Common Speech, the Westron as it was named, …
It appears at various other places in the Appendices other than the place you mention. I agree that Westron or the Common Speech “is feigned to have been turned into English”.
What I was saying was that
examples of actual Westron nowhere appear but in those names, not mentions of the Common Speech or Westron as a language.