Bought Penumbra collection a few years back from the site- steam code?

[Bouc]

Hi all,

I've been a huge Frictional Games fan for ages. Way back when, I bought the Penumbra collection (overture, black plague, requiem). It came as a single dmg download. I was wondering- is it possible to activate those games on Steam? There's no serial or anything in the dmg. I already bought overture on Steam because I forgot I actually owned it, but I'd like to not need to buy black plague again.