Mark,
I know you wrote a very good book on the Lightweight, indeed it is well-thumbed as the one we all go to for information and we're all grateful, but it isn't the only source of information we use. For you simply to say, "you're wrong" without any explanation is both arrogant and rude.
It is also extremely unhelpful. If you think it is from an entirely different Contract to the one shown in the Taylor/Fletcher book, for 19FM20 to 26FM13 or chassis numbers 951-01059A to 951-02555A, then justify yourself, say why and make it clearer for us all.
Of course, it might have been nice if you had replied to the original post rather than waiting for others to try and help then shooting them down with a one-liner.
I don't claim to be an expert, as you do, and, if I am wrong, I will both apologise and accept the correction willingly, as I would like to know the truth as much as, I am sure, you would enjoy enlightening me!