OS X Mavericks :: Moving Time Machine From One Drive To Another

My existing Time Machine drive was running out of space so I decided to get a much (much) larger drive and move everything over from the one to the other.  In doing so, I followed the directions on this page 

Time Machine: How to transfer backups from the current backup drive to a new backup drive up to around step 9.  That's where I deviated a bit. Initially, I did just drag the folder "Backups.backupdb" from one to the other but after 5 hours of spinning it's wheels, it informed me that it had about a day to copy all the data from the old drive to the new.  I didn't have a day (again, stay with me).  So instead of copying, I figured I'd just start moving all the files.  That way, even if I had to shut down my laptop (which I did, to come in to work), I could just stop the process and pick up where I left off -- the system wouldn't have to re-look at files that it had already processed.  So I just opened terminal and ran 

cd /Volumes
sudo mv -fv <OLD DRIVE> <NEW DRIVE> 

and everything seemed to be chugging along just fine.  I let this process continue running over night and this morning, it was still working on the very first (ie oldest) backup directory.  I aborted the process (^C), ejected the drives (and they ejected just fine -- no errors, no warnings), shut everything down and came in to work.  Got in to work, plugged both drives back in (again, everything is fine) but when I went to kick the process this time (same commands as above), I keep getting the message "Operation not permitted" for every file and folder.  Huh?  It was fine with this last night. 

So then I open up a couple of finder windows (one for each drive) and this time, I drag over just one folder from 

<OLD DRIVE>/Backups.backupdb/MACHINE_NAME/ 
to 
<NEW DRIVE>/Backups.backupdb/MACHINE_NAME/ 

and, after I authenticate, I'm given the error : "The operation can't be completed because backup items can't be modified" ...

In finder, when you start a copy process, OS X creates kind of a "ghost" folder/file in the new location and in finder, it appears to be kind of greyed out.  When I started the copy process (before it told me it was going to take about a day), it created the ghost "Backups.backupdb" folder as usual.  But after it told me that it was going to take a day and I cancelled the process, the ghost folder remained and still appeared greyed out in Finder.  In terminal, I was able to change to that directory as normal so I didn't think anything of it -- the directory just existed.  I cd'd, moved files and all was good, as I said above. 

After I ejected the drive, I expected that when I mounted the drive again, the folder would appear as normal in Finder.  But it's still showing greyed out.  And I can't double click on it to open it as I can the same folder on my <OLD DRIVE> time machine.  I have to right click and select "Open in new tab", which it will.  When I do, though, the directory appears empty despite the fact that if I change to that directory in terminal, it's populated with files and folders that were moved last night.