Yeah, I know...or rather knew both of the gentlemen in question. Don was an instructor-ranked student of my Si Dei "younger kung-fu brother", Robert Jacquet in Leung Ting's "Wing Tsun" lineage in the '80s and early '90s. He broke off on his own back in the 90's. Phil Bradley was a promising student of my Si-Hing or "elder brother" Keith Sonnenberg at about the same time. He also left to go on his own. Personally I was friendly with both, and respect peoples' right to follow their own paths (I myself have switched organizations). However, neither of these gentlemen were anywhere near what I would call "master level" back then, and from what I've seen and heard, are still not at that exalted a level now. Of course I may be mistaken.
Secondly, like many others posting here, regardless of lineage, I do not believe that you can effectively learn WC/WT/VT by correspondence. If you are studying under the guidance of a teacher, videos and books can serve as a reference and provide excellent supplemental information...but that's about it. My advice is to find a qualified instructor and learn directly from him. "Vale mas el modo viejo" --the old way is better!