as for Lam family, left handed "Si family plum flower spear" (Si ga mui fa ying cheung 史家梅花櫻槍) was incorporated into today's Lam Ga Hung Kyun curriculum by Grandmaster Lam Saiwing.
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Grandmaster Dang Fong has learned "left handed plum flower spear" (jo sau mui fa cheung 左手梅花槍) from monk Singling 冼靈大師 of the Wa Lam monastery 華林寺. i have never seen it, so i cannot say if it is same, similar or different.
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there is a video of Wing Lam sifu here http://www.wle.com/products/VHG15D.html
some of the techniqes are similar/same, but the sequence is different - it
is not our Si ga mui fa ying cheung. Wig Lam sifu calls his spear se "four gates plum flower spear" (sei mun mui fa cheung 四門梅花槍)
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i do not know how the set of Lau family looks like, but Grandsmaster Lau Galeung has shown many techniques form the Lam Saiwing's set in the movie Challenge of the Masters, and in this video, he demonstrates superb (not only) spear skill
[youtube]http://www.youtube.com/watch?v=KEQIWQAEAoY[/youtube]
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another Hung Ga spear, from Singapore
[youtube]http://www.youtube.com/watch?v=F88m_0c8ZJM[/youtube]
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anyway
- mui fa cheung is a common name for spear sets
- the basic moves (basicly 3 moves- down, up, shoot) are the same everywhere
all the best