http://hkmdb.com/db/movies/view.mhtml?i ... ay_set=eng

I changed the film to point to the 1998 Taiwan animated film. (The Chinese characters to the naked eye looked like the same as the the graphic for the VCD at YesAsia)

http://global.yesasia.com/en/prdGrpDept ... /did-7497/

There may be additional information that needs to be added in.

IMDB claims the following:

http://www.imdb.com/title/tt0223391/
Directed by Siu-Di Wang
Wen Ying .... Grandma (voice)

Here are some better links elsewhere:
http://www.usc.edu/libraries/archives/a ... n/ama.html
http://www.kinema.uwaterloo.ca/gran022.htm

And what appears to be the complete cast here:
Google Link

I am not sure if Helen Law was involved with this, based on the credits I've seen.

Helen Law Lan is the voice of Grandma on the Cantonese track.

According to the Winson link, other credits include Sandy Lam San-San, On Tak-Juen, Pau Hei-Ching, Jamie Luk and Joe Cheung Tung-Cho, no doubt also the Cantonese track.

added prod., prod. manager, dir., writer, original comic author, mus., ed. and 8 voices more.