Thank you. I have read Iain Sinclairs books and enjoyed them, although they do require a good deal concentration for the full benefit. I particulalrly enjoyed 'Landor's Tower', which struck many chords with Houdini.
The fellow who told me of the wonders beneath Londinium was himself aged, and I suppose the era we are looking at would have been the 1920's/30's. I have smeaking suspicion that the blitz may have played a part in actually uncovering the artifacts. I shall consult the family album for more details.
The London Stone is quite the most sad method if exhibiting that I have come across. As I type, Houdini is plotting a liberation plan for the sad little megalith.