Copy file permissions, but not files in Unix

(From : https://stackoverflow.com/questions/15245144/copy-file-permissions-but-not-files, closed because off-topic)

I have two copies of the same directory tree. They almost have the same files in both (one version may have a couple extra or missing files). However, most of the files are in common to both directories (have the same relative paths and everything).

Assume these are in directories:

version1/
version2/

The problem is that the permissions in version1/ got messed up, and I would like to copy over the permissions from version2/, but do it without replacing the files in version1/ which are newer.

Is there an automated way to do this via shell commands or scripts?