Just a thought Alex. How about opening just SusCo on a read only basis and opening it to the search engines. Put a note at the top of SusCo that only members of SusCo are allowed to post, saying nothing about SilCo or The Tin Ceiling. People who ask good questions or make good posts could be invited to join Silco and The Tin Ceiling.

I think this would be a way to find new members without exposing the more sensitive areas. It would also be a way of offering the great storehouse of information in Susco to those who could use it.