Hi guys,
We exercised this thought train on an earlier thread last year sometime. The basic conclusion is that Dragon, Pak Mei and SPM all came from the same kind of stuff, - the three masters were contemporary, and there was the power dynamic added from Southern White Crane, the 'faat ging'.
The external stuff is all mostly hakka family style stuff. Loong Ying has more heavy power, Pak Mei and SPM are more 'springy' - SPM uses dynamic tension, Pak Mei uses hyper extension to get there. The end result is rather similar to my superficial examination.
Yes, Cheung Lai Cheun and Lam Yeu Gwai grew up studying together, and shared a kwoon as young men. They studied from Lam's father, I believe, who studied from a monk "Hoi Fung Sim Si" according to my Dutch mates.
The SPM link, which I can't remember exactly, is contemporary. Perhaps someone else can chip in. 1900 to 1930s is the period in question.
Guangzhou Pak Mei Kung Fu School, Sydney Australia,
Sifu Leung, Yuk Seng
Established 1989, Glebe Australia