Wrong about the fate of the young actor
Although the communist regime had not been happy about the American Oscar to the young Ivan Jandl and he had certain problems by his further casting due to this, he had never worked in quarry as repeatedly mentioned in few comments.
He had continued playing in few children films back home in Czechoslovakia, later as an adult on theater. He had gone through different jobs but never in a quarry. Look on his Website http://www.ivanjandl.com/ and his pictures from the later days http://www.ivanjandl.com/galerie.htm