I think several of the (C&C) modules are oop along with their d20 counterparts.
I've only been a TLG fan for a year or so, but I've bought every C&C product they have, and except for the Castle Zagyg properties, they are all still listed in the on-line store. Even the Personalized leatherette PHB and M&T are still listed on the Store as is the White Collector's Box set. It wouldn't make sense for them to allow any C&C product to be OOP as it is their main product line. Though if I have missed something someone please let me know.
The D20 stuff pre-C&C is OOP, but lucky for us is slowly being converted (i.e. Heart of Glass this month).
Crusaders have limited print run, but are available as pdfs.
Sir Dachda McKinty,
Margrave and Knight of Portlandia
Castles & Crusades Society