@seb192 

try   chmod  -b

@seb192,

Since most files have permissioned inherited, it should be ok, unless someone changes the permission.

chmod -Rb 750  

Hi @seb192 ,

as you point out, as soon as you add inheritable ACEs to a directory, any new files created are created with an ACL formed from the inheritable ACEs on the parent. If you added those using "chmod +a ..." the original POSIX modes will have been converted to ACE entries.You could recursively remove those inheritable ACEs. You will still have ACLs but they should then match the previous POSIX permissions. 

I do have a question. Do you want to revert to POSIX permissions or do you want to use ACLs and have the owner/group have permissions when they create new files? If so, you simply need to add additional inheritable ACEs to the directories of the form:
chmod +a creator_owner allow generic_all,object_inherit,container_inherit,inherit_only d1
chmod +a creator_group allow generic_read,generic_exec,object_inherit,container_inherit,inherit_only d1
That adds two inheritable ACEs that will grant specific permissions to the owner and group on create. Obviously, you'd need to recursively apply those to directories below the top of tree.

I'd like to revert to POSIX altogether.