It was postrelease nonstandalone DLC and as such I refused to buy it on Steam.
Later I rebought the game on GOG which has it integrated, but never replayed that version.
Hi ya Joxer my friend! DLC ,,eh? OK I have just bought the Gold version from steam mate. Includes the 3 DLC's. These game stores make a packet out of us gamers buddy! Thanx again my friend.