It is my understanding that Da Shifu Al Moore Studied in Bay Area prior to WWII. Then sometime after WWII he went to China and completed his Martial Art studies. Shou Shu is the name he developed for the Martial Art that he learned. It is my understanding that he did study Tracy Kempo in the late sixties and received his 3rd degree in Tracy Kempo. Some of the early moves in Shou Shu were Tracy Kempo moves but with different motion and timing. Many people say that Shou Shu is modified version of Tracy Kempo. However many people believe that Shou Shu is something completely different. The only way to really learn about Shou Shu is to go to one of there schools in California. In the early years Shou Shu did use Tracy format for instruction.
Al Moore, his brother Ralph Moore, and Al's son Vern (Al Moore, Jr.) were Tracy Kenpo Karate students in the early to mid 1960's. They were beginner white belts with no prior training. They did not ever study directly from or with any of the Tracy brothers, but did study under assistant instructors Steven Labounty, Bob Blackmoore, and Ted Sumner. Mr. Labounty passed away recently, Mr. Blackmoore passed away about 20 years ago, and Mr. Sumner lives in Texas and still teaches part-time. I spoke with Al Tracy on the telephone in 2008, so that is where I got this information. After earning their 1st degree black belts, Al, Ralph, and Vern moved on to study a style called BoK Fu Do (System of the White Tiger) from Richard Lee in the late 1960's. Al and Ralph earned their black belts in the late 1960's, and Al Moore, Jr. earned his black belt in the early 1970's. Kind of odd that it wasn't a sash considering Mr. Lee teaches a kung fu style. Mr. Lee was a former high ranking Tracy kenpo black belt that broke off and started his own style. After earning their 1st degree black belts, the Moore's took over the lease of one of Mr. Lee's schools and opened their own school teaching their Americanized made-up style of Shou shu, which is simply just a blend of what they learned in Tracy kenpo and Bok Fu Do packaged under a fancy name with a slick marketing plan. Shou Shu has elements of Shuai Jaio or Chaio (pronounced "shu-ee-jow", Chinese wrestling originating in Beijing), which makes sense considering Mr. Lee's style would have a bit of that in the curriculum.
I have heard many different backstory's from those that are part of the Moore's chain of schools, however, nobody has been able to provide names of any Grandmaster's in China, pictures of training, tea ceremonies, copies of passports, etc., to substantiate any of the stories that I have heard about Al Moore's supposed training in China sometime after WWII. I did hear of someone named Lu Chin but no kung fu expert that I've spoken with (Doc Fai Wong, Tat-Mau Wong, the Lacey brothers. etc.) has ever heard of this person, if he ever existed.
One last thing, I find the combining of kung fu uniforms and a Japanese belt system to be quite odd. Richard Lee does have a similar uniform as well as small circular patches representing his organization, so I understand where the Moore's got their uniform system and animal patches on the belts. Karate is heavily influenced by the Chinese martial arts, so maybe that is why Al Moore decided to combine the two. Outside of the United States, one will never find this in Japan or China.