[GraemeJ]

I backed up the whole library and then set the external card path, as outlined by Mike a couple of posts above. Restored and it all worked well - everything is now located on the removable storage, as I wanted it to be. Since it seems that I can create sub-directories under the obligatory one, I'll probably follow Skip's lead and do some minor re-organisation for ease of access.

I also agree that this is a point which should be emphasised in the manual - many of us would not expect this Google limitation.