Welcome to the Forum.
Sorry you have had to wait for a response for so long. It would appear to me to be possibly a product of the Wang Hing workshops. As the firm were in business for nearly 90 years they used a large variety of marks and no doubt at times punches became worn or broken.
Another possibility is another Hong Kong silversmith whose name is undocumented but used the mark 'WHL', your mark may be a partial striking of this mark.
There are members with a far better knowledge of Chinese marks than me, and are only occasional visitors to the website, hopefully one of them will drop by soon.