Hi Janos,
Copy files from another Oracle Software is not a wise idea. Even if this would work, it is an unsupported way. No one could predict what would happen later on.
I said to rsync the file systems not to copy specific files, If you rsync the file system (Oracle_home) it syncs all the binaries without any difference between source and target. It doesn't require uninstallation and re-installation of Oracle.
Deinstalling and reinstalling the Oracle Software is the most easiest and quickest supported way
I did this rsync even on new systems where Oracle was not installed, it worked all the times without any issue.
Never mind - It is just another solution to resolve the issue and not to challenge 
Regards,
Nick Loy