Mom's Memoirs:

My father was the son of exceedingly well-to-do parents from Lodz (which was under Russian domination)  my grandfather (Herman Jonas) produced woolen fabrics, worsteds, which were indestructible.[1] I remember this because I had a coat, cut down from one of my mother’s, which she had gotten tired of wearing! There is some memory of having been told that my grandfather drove in a Troika to Russia to sell his materials. 

...

When the Russian revolution broke out, my grandfather Jonas got cut off from all his sources of income and my father had to fend for himself. 

...

During the war they [Aunt Fania] were in the Warsaw ghetto - her father died in the ghetto of pneumonia - she helped nurse him.

From Draft Letter to Evan for his Bar Mitzvah:

My paternal grandparents lived in Poland, and [I] only visited them twice, at age 7 and again at 15—traveling abroad was not easy in those days, passports, visas, permits, etc. 

Inna Pistrak's Memories:

I know that our family fled from Poland to Moscow in 1915. 

,,,

I don’t remember when exactly grandfather Herman and his family returned to Poland.  But I know that Fanya was crying bitterly, she didn’t want to leave Moscow and the Conservatory. I often think that if she had stayed she would have escaped the torture of the ghetto and the Auschwitz. But she could also end up in Gulag, as many others. Who knows…

I remember that we got the chance to send food to Poland, to the ghetto, when Stalin and Hitler were good friends yet, in 1940-1941.

Grandma Clara visited us in Moscow once again in 1928, when I was about 8 months old. I have a lovely picture from that time: grandmother and my mother are sitting in the hammock, mother holds me in her arms, and 7-year old Misha is standing next.

Grandmother died in 1937, just before the terrible times began.

I don’t know how it happened that her family was scattered around Russia: her brother Isaac lived in Moscow, her sister Percha – in Ivanovo, and her sister Rebecca – in Leningrad. Rebecca had two daughters Marussya and Lucya with who my mother was in touch till the end of their lives.

Grandmother’s maiden name was Bernstein, and my mother somehow believed that she was from the same ancestry as the great American composer and conductor Leonard Bernstein. She even used to find some typical family features, telling me that I looked like “a typical Bernstein”, blond and blue-eyed. But my hair became dark with years.

Notes:

1. The wedding certificate of Mom's parents describes him as a (in French) a "fabricant" (manufacturer).

Geni data (Herman)

Birth: circa 1859 Grodno

Death: February 13, 1942 (82) Warsaw

Place of Burial: Warsaw (Okopowa), Warszawa, Województwo Mazowieckie, Polska, Republic of Poland (Poland)

Immediate Family: Son of Rafael Hakohen Jonas
Husband of Klara Jonas
Father of Rafal Jonas; Pola Rafalvna Jonas and Fania Uryson

Geni data (Clara)

Birth: circa 1867 Moscow, Moscow, Russia (Russian Federation)

Death: 1937 (65-74) Lodz

Immediate Family: Wife of Herman Jonas
Mother of Rafal Jonas; Pola Rafalvna Jonas and Fania Uryson
Sister of Isaac Bernstein; Percha Bernstein and Rebecca Bernstein