Did you check Yad Vashem records? plugging in SLIVKEVICH there are 98 records. Places in Poland are mostly Lodz; some unknown places in Poland. Possibly someone who created the page of testimony could prove to be a contact.
Beverly Hills, CA
Researching: GOLDMAN, STEINER, LANGER, GLUECKSMAN, STOTTER in various parts of Galicia, Poland
(Nowy Targ, Nowy Sanz, Wachsmund, Dembno, Lapuszna, Krakow, Ochotnica) who migrated into Kezmarok or
nearby towns in northern Slovakia and Czech Republic (i.e., those who lived/had businesses in Moravska Ostrava);
GOLDSTEIN in Sena or Szina, Szkaros and Kosice, Slovakia; Tolcsva and Tokaj, Hungary.