Just as it sounds, I'm trying to find out if there is a (standard) command that will produce a diff of the permissions between two files and/or directory trees.
Ideally it would put out a patch file that could be used to change permissions to match the target, though I'm guessing since standard patch files are interpreted by ed, that it might have to be a separate format.
You could always do something like this to get the differences.
It would then be trivial to hack up something that performs the require changes.