I just read in an International Screen article that Kong Hung (or Chiang Hung) is the actress Tong Dan, who worked in Shaw's Cantonese division. She adopted the new name when she started working at Cathay.
Kong Hung
http://hkmdb.com/db/people/view.mhtml?id=3441&display_set=eng
Tong Dan
http://hkmdb.com/db/people/view.mhtml?id=1024&display_set=eng
A look at the HKFA catalog confirmed this.
http://ipac.hkfa.lcsd.gov.hk/ipac20/ipac.jsp?session=1D2715818RS76.111&menu=search&aspect=basic_search&npp=10&ipp=20&profile=hkfa&ri=&index=NAMEBRP&term=tong+dan&x=0&y=0&aspect=basic_search