What size single convext Yunzi stones do I need?

[Faro]

I bought my Go set from YMI in around 2007 or so. It is a Chinese Standard size board with double convex size 33 Yunzis. I always thought it was kind of odd that the board was Chinese standard and the stones were double convex. A weird clash of China and Japan. It was probably just their inventory at the time.

At any rate I'd like to switch the double convex out for single convex. On YMI's website it says size 3 single convex will fit Chinese, Japanese, or Korean standard board, but if you go to the FAQ page about stones and stone sizes the chart they have posted says size 5 stones are the norm for Chinese standard boards. YMI also does not sell size 5 S.C. stones right now, so I worry tracking them down might be difficult and possibly expensive. (Size 3 stones are only 25ish dollars)

Will I be fine with the size 3 S.C. Yunzis' or will this require some hunting?

Also, I just had a thought regarding if the Jujube Kitani bowls that I have (The ones that come with most YMI sets) will fit the single convex stones?

[EdLee]

It is a Chinese Standard size board with double convex size 33 Yunzis. I always thought it was kind of odd that the board was Chinese standard and the stones were double convex. A weird clash of China and Japan.

Were the Yunzi (which in is Chinese language) stones Chinese or Japanese ? If the Yunzi stones were Chinese, where did 'Japan' come into the picture ?

if the Jujube Kitani bowls that I have (The ones that come with most YMI sets) will fit the single convex stones?

AFAIK single convex stones are usually 8-9 mm thick or less (versus double convex which can go over 10 mm thick ), so they should fit.

[Bonobo]

My single convex Jade Yunzi stones (probably ~45 years old):

4 mm thick (~0.16"), diameter 23 mm (~0.9")

They fit perfectly on all of my Go boards.