Question about gifting retail game w/required Steam Activation

So I own a physical copy of Fallout: New Vegas. It forces you to activate it on Steam. After playing it through, I removed it from my Steam account by contacting customer service. They required a photo of the game, and the serial number, etc.

Anyway, now the retail version of the game is ready to be used by someone else. My question is, could I gift it in SteamGifts with just the cd-key that comes with it, or does someone need the actual dvdrom to install it? I located Fallout: New Vegas on the FAQ list of Steam activated games in the sticky thread here, but I don't know if that means my version needs the dvdrom or not.

Tanks.