The basic rules for a witness statement are that you can say what you witnessed yourself, you can say from whom you heard something and you can point to documentation which proves something you say. To be fair, he does refer to documents which prove his family tree but he does not exhibit (via the text of his statement) any documentation (which could have included letters, contemporaneous notes, photographs etc.,) relevant to the issues in the case. He doesn’t even date the various events he reports. A witness statement without dates is practically useless.
The purpose of a witness statement is to give evidence. It should not contain legal arguments – they are made in the pleadings to the court, in written skeleton arguments and orally by an advocate. Courts are used to litigants in person confusing these two aspects of a trial. (Excerpts from http://blog.scrapperduncan.com/)