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YIVO replied and they have a collection of Lidski. Whether they have the tikei kesef we will see.
Anyhow, I find the description in the book reliable enough and think we can accept that Sheftel was Dov Ber's father. Did Rabbi Zecharya Mendel Klausner, of Krakow have any known relatives called Sheftel who could be Sheftel father of Dov Ber?