Thanks for the replies gents. I completed the cellar yesterday and I've made a start on mass painting the rest of the interiors tonight.

As to how well they work or what issues may arise, I'll report back when the time comes. I don't see record-keeping being an issue though, as there won't be any. All of the interiors will be laid out in a logical order next to the main (i.e. outdoor) playing surface. Furthermore, as CinC uses card-based activation, there's no worry of forgetting about models who are off-table.