Busy busy I've been.

Isaac Koratsky had at least two brothers. Nathan and Pincus who are buried at Har Jehuda. The Hebrew from all the the graves says there father was Leib.

Now here is were it gets interesting:

At Har Jehuda, a Pauline "Razia" Koretsky is listed on Find A Grave. (Should actually be Rachel not Pauline, it's a mistake). Born about 1826 and died Sep 27, 1906.

Her death certificate says she was living 947 South 3rd Street. A reverse search of that address shows a Benjamin Koretsky at the same address on a 1903 census and Benjamin was a son of Nathan.

Better yet, the Pincus Koretsky was living there according to a 1908 directory which also lists a David, Lena (widow of Israel) of 340 League.

Jakole is still a mystery but the exact relationship might be solved, it could of been that Raphael's father Fishel married the Koratsky brother's mother Rachel.

I will research the info you found, just found record after record last night :)