http://hkmdb.com/db/people/view.mhtml?id=13165
http://hkmdb.com/db/people/view.mhtml?id=21876
I think that these two actors are the same person. In A Woman, a She-Wolf (http://hkmdb.com/db/movies/view.mhtml?id=11205), he's credited as ????????. Also, THIS photo of Chou Ta-hsiang has a caption that, while unfortunately not completely readable to me, mentions Lan I-feng (specifically I think it says ??????? - the Lan I-feng period) and the titles of some of his songs.
If everyone agrees they are the same person, I think his primary name should be Lan I-feng, since he seems to have been better known as a singer (using that name) than an actor. It also looks like he only ever released one song as Chou Ta-hsiang.