I think Cheung Jan (1)
http://hkmdb.com/db/people/view.mhtml?i ... ay_set=eng
is an alias for Cheung Ching-Fung
http://hkmdb.com/db/people/view.mhtml?i ... ay_set=eng
I know that in four films (Black Bull and White Snake, Magnificent Chivalry, Fearless Fighters, and Iron Swallow), Cheung Jan is in the cast list and Cheung Ching-Fung (not credited) can be seen on screen.
Another bit of evidence is in the film Young Flying Hero. Cheung Ching-Fung is credited on the poster and on-screen credits, but the HKFA gives credit to Cheung Jan.
Does anyone have further evidence that Cheung Ching-Fung and Cheung Jan (1) are the same person, or contrary evidence that they could not be the same person. (Is Cheung Jan (1) credited for any films in which Cheung Ching-Fung cannot be seen?)