I find this fascinating... if not for Shenmue, I probably wouldn't have learned about this place until much later. I wish there was more photo and film/video documentation of it.
I bought this book years ago for like $80 and it has some of the most amazing photos of Kowloon. It's even more pricey now, but I'd highly recommend it.
What a fascinating place, the shenmue version isn't anywhere near as dense as the real version, but more like how the city might have been in the 1960's, with less buildings.