Where are notes stored in Mountain Lion I ha a hard drive that died recently in my macbook, I've replaced the hard drive etc so no issues there. Unfortunately, it appears I wasn't backing up the notes app to iCloud, and I really need to get some back...

I've managed to get the hard drive spinning in a usb dock that I have so I can access it, but I don't know where notes was storing it's data. Any ideas?
They're in ~/Library/Containers/com.apple.Notes/Data/Library/CoreData/ExternalRecords/.

You can probably just copy the whole ~/Library/Containers/com.apple.Notes/ folder from the old installation.