The "curse" (and our lucky) of these kind of expasion packs is that they were developed by
Formgen, Inc instead of
Id Software.
The company FormGen was bought out by GT Interactive in 1996.
http://www.mobygames.com/company/formgen-inc
They are sold at
Amazon Marketplace, but I haven't found other buy links.
Only Spear of Destiny is sold and supported at
IdSoftware.
So I would say they are ok to add
