Due to a change in some software I use (Yep 1 > Yep 2b), I now have two separate sets of documents sorted in subfolders by date:
1. the older set enclosed in a folder I'll call "Old files" (for purpose of this question);
2. the new set enclosed in a folder I'll call "New files" (for purpose of this question).
The old files were filed by date added according to year and month (e.g. 2009 > August).
The new files are filed by date added according to year, numeric month and date (e.g. 2009 > 8 > 31).
I'd like to consolidate the two collections by re-filing the contents of "Old files" in with "New files".
So I'm trying to figure out a Hazel rule that will let me do this as a one-off action. I've created a rule I thought would do it. But on running the "Preview rule matches" I get a list which has only a list of folders down the lefthand side matching the current Year folders in "Old files", and the righthand column is blank. This has rather confused me! Presumably I've done something wrong but can't figure out what.
A sub-question is: If I define the rule by date added what will happen to the "Old files" which were originally filed by year & month added but not "date added"? i.e. does my system have in its metadata a "date added" for each of the "Old files" even though they haven't been filed that way?
Hopefully I've covered all the issues for this one-off operation which I'm hoping will be over in seconds!?

Thanks.