My game was running fine until I got to the British Museum part with Nico. I went to talk to the Museum attendant and the game just froze for no reason (apart from the music). Unfortunately my last save was in Marseilles Dockyard, so I downloaded a save point from Caribbean Island from a Broken Sword website, but I have no idea where to put it in order for the game to recognise it.
I imagine I would have to put it in the same place as the save file from Marseilles Docks is, but I can't find it anywhere, not in the SCUMM folder or the main folder or anything.
Any help would be much appreciated.

It might be the old vista 'relocating non-admin data' trick (assuming you have vista). Have a look in
C:\ Users \ <username> \ AppData \ Local \ VirtualStore \ Program Files
and see if there's a Broken Sword folder somewhere in there. App Data is a hidden folder by default

My game froze on the exact same place. Also Running Vista.

The first thing I do with ScummVM games, is to specify the path to a Saves folder under options.
I've actually made a SAVES folder in my Games folder and then point all the different games save folders to it.
That way it's easy to find my saves at all times. Would look something like this:
C:\Games\SAVES\BrokenSword_2
and
C:\Games\SAVES\FeebleFiles etc.
Oh and I found out BS2 didn't add the cutscene by default - I had to point the Extras path to the Extra folder before it would work.