https://www.youtube.com/watch?v=3_qEeeuReyA
The video above ( uploaded on my channel, which contains now over 200 score-videos of Zelenka, if you didn't know ), the recordings referenced were obtained from extensive searching throughout the internet, after having studied the "historical" recordings section of this website, found here:
https://www.jdzelenka.net/cds-recordings-historical.php
I plan to obtain the rest eventually, if possible - and upload them to Youtube also. But they are incredibly rare, most likely expensive - and possibly vinyls, which if so, would be quite difficult to transfer to a computer.
Yours sincerely,
Jamie Holdham