Finding the Hebrew name of a deceased person

I have tried in the past with no success to find out my late father's Hebrew name, including through the Prague archives.
Has anything changed now that there is a new Data Base regarding birth registration?
Defining the problem: My father was born on May 20, 1901 in Prague. His parents were Karl Thein and Francis Burger. He was officially registered as Ernst, however, like every Jewish boy was given a Hebrew name at the time of circumcision. I was informed in the past that the Hebrew name would have been registered in the book of the Mohel that performed the circumcision, but that these books were either lost during the Nazi period or were transferred to Russia during the Russian occupation and therefore were not available.
Can anybody inform me if this information has now become available and if so, from whom or from where?