Small Rice Grain Bowl

[tigershep]

Hello!
I am trying to identify a cute little bowl that has been in my possession for a number of years. Today I finally found out that it is a rice grain bowl.
I am interested in learning of the mark on the bottom, but especially the age. It is in great condition, although there are paint smudges under that glaze which make me think it isn't of the highest quality.
Pics to follow.
Thanks!

[tigershep]

Pictures

[Stan]

I believe this is 20th century, on the later side I think, the mark is off centered and the porcelain foot unglazed area looks to smooth and it is perfectly round, not sure about the mark almost looks Vietnamese, the top mark Wan.

[peterp]

It is Wan Yu (??).  The characters are a bit close.

[Stan]

Thanks Peter.