Gam Ka Fung 甘家鳳 shd be Gan Jia Feng and not Gan Gu Feng.
I notice that the word 家 in some names is quoted as "gu" in hanyu pinyin instead of "jia". Although, the dictionary does support both translation, Jia converted to cantonese "Ka" is more close in sound. So far, I have not read any name in hanyu pinyu which state 家 as "gu".