Genuine Yellow Lake Hone

Hi:

I recently picked up a Geniune Yellow Lake Oilstone in the red box with two triangle shapes on each side of the label, which I believe is not the Salmens brand. I know this has been discussed in previous threads, but has anyone worked with this much? I know these have been reported to have a huge variation in fineness.

Also, how would this sit in comparison to a "Fine" grade Tam O'Shanter?

Thanks.

this is what i have read a fine tos is around 6k- 8k maybe 9k at the most the yellow lake stone ( a b salman) is at 8k with water the edge is much improved with oil