How to move items from a bespoke "Archive" vault to the official Archive/Trash

Tags would be useful because I want to move vaults, before I archive. I had hundreds of passwords in my "legacy vault" and moving them as-is would just mean they got jumbled with my active passwords. I ended up doing a manual move in batches of ~10, but unfortunately even that hasn't worked correctly and I now have a bunch that missed tagging (and subsequently missed archiving) and are now jumbled up in my current vault (which I was trying to avoid). In my opinion the Windows v8 drag and drop feature is a bit busted at the moment (but that's a little off topic given the original query above was for v8 Mac).