In choosing Millwall as a venue, I wonder whether IL had this in mind? - London Broncos played some of their early SL matches at Charlton (very close to Millwall) and got some very good crowds. IIRC, they had over 9000 for a Saturday afternoon televised match against Paris. At that time, the London club did some great work in drumming up support in Kent (Millwall's traditional heartland) - after all, the only rival sporting clubs in Kent are Gillingham FC and Kent CCC.