I have the stone you are asking about and it is not a finishing stone, it is a pre-polisher. Mine has a crack down the middle which makes 30% of the length unusable. I use it to finish pocket knives. I think it's a little bit smoother than my kitayama. You could do some interesting stuff with the right slurry.

Mark does have the ozuka in stock now. I think it's also too soft for finishing. I kinda wanna get it anyway, maybe cut it up and make it into slurry stones.

My recommendation is to contact a dealer and tell them you are looking for a razor finisher. Those will run you about $200 for a small one and $300 for a normal size. You can probably find a super thin one like 10 mm for closer to 100.

Maksim at japanesenaturalhones or takeshi at aframestokoyo can pick out exactly what you need.

Oh btw I just joined this forum. I was reading threads and thought I'd add my 2 cents since I own the stone in question.