Hi Eric and All,
Indeed, I am familiar with GM Chiu Chuk Kai (his my teacher). BTW this year marks his 15th year since he passed away.
Here's a clip of me explaining the variation and the same technique on the top right corner of the scanned page. Thanks for bringing that up.
Eagle Lands on a Branch and Hero Wu Song Strikes Tiger
Wu Song Da Hu
About the Luohan Gong, I happen to practice this set and also conducting research about the origin of this set. The manuscript is part of a text called "Luohan Xinggong Duanda" (Arhat exercises merits short strikes) which is dated around mid 1700s. Personally, though I may be biased, your supposition on the connection of your Luohan and this set is IMHO heading towards a possitive direction. There are many Luohan material out there but none has been so well documented like this set. It adds to the credibility of authenticity in my mind.
As you said, Wulin Yi Jia (martial arts forrest is one family). Hopefully, more people will see that and we could achieve Tian Xia Da Tong (the world is of grand commonality).
On a side note, the kick that you saw in the my clip is what I believe to be an integral component in the San Zhan stepping method. IMHO It is supposed to be trained all the time but the application is seldom explained which is why some lines dropped it altogether. The essence of crane method is in the stepping (now that's some truth). Sad thing really that people leaving things out but... I also saw this type of footwork component in Fanziquan BTW. So...
Warm regards
Robert