Updating from the huge and clear credits here :
https://www.youtube.com/watch?v=yQ9RY2wK3Fs
... it is evident that ...
Love Flowering Rain (1977)
https://hkmdb.com/db/movies/view.mhtml? ... ay_set=eng
... is a duplicate of ....
Love in the Spring (1974)
https://hkmdb.com/db/movies/view.mhtml? ... ay_set=eng
I couldn't match the job for 葉宗麟, as his other listed jobs don't match.
https://hkmdb.com/db/people/view.mhtml? ... ay_set=eng