The others are modified Dwarven Forge pieces..
to avoid to damage original DF pieces and to work with soft material, I made a Silicone mold of some DF piece, then I've casted them with plaster (an hard plaster).
then with a nippers I've "ruined" these pieces one by one..
The idea to modify DF pieces to obtain ruined pieces, was born to avoid the nightmare of the overseas shipment with customs and no informations on the package for many days, but all the process was very time consuming (I had also to paint them) and no cheap..my conclusion at the end, is that was propably better to buy directly the new Ruins Set :-D
So I will suggest only the Hirst Arts part, that give the possibility to raise the height of the ruins very easily and allows a lot of different combinations using different ruined walls in the middle of a room.