According to Jerry Schimmel, author of Chinese-American Tokens from The Pacific Coast:

The top one reads YUN (cantonese) "fountain" or "source," a common device used on both chips and tokens. "Source" is the meaning in gambling, that is "source of wealth or luck." The bottom one is as you say, WUI, or remit, that is "Good For." There is no numeral anywhere on the piece, so we don't know it's gaming value. Sometimes they used colors to designate value.

Was wondering if I could use your scans for my web site on Chinese Inscribed chips?

John