I remember this very well. I can also remember when you could look inside it. I tried it again a good while later but you couldn't do it anymore. Fun while it lasted though!
You'd think these would be all over the place in London since Doctor Who is so popular. I am glad they didn't start making a bunch though because it would just get all touristy and stupid. And when you find the rare one like this this, it must be sooo cool!