I have to agree with this. Although Wilson's books are a great read - I have most of them - I feel that he does not particularly do any new research but merely gathers information from previously published works and edits it into a new book. Hence the mistakes, that could and should be corrected.
With regard to his two-volume work on engraved guns, I was led to believe that if you had a pistol that was worthy of inclusion you could pay him to have it in the book!
Rio