My guess:
Ruined Smithy (or Lab): +2 cards
(reason: we have 2 cost cards that give +3 cards, put one back (Courtyard) and +2 cards with extra effects (Moat,
Steward)
Even +2 cards seems like a substantial step down from what we have already and matching the value of a buy.
Ruined Village: +2 actions
(reason: we have 2 cost cards that give +2 actions, but always give extra things (Native Village, Crossroads for the first, Hamlet for a discard)
Ruined Festival or something: +2 coins
(reason: we have 2 cost cards that give +2 coins, but always provide an additional effect (Duchess, Embargo)
Ruined Market: +1 buy
(reason: we already know this one)
Ruined Chapel: Trash one card from your hand
No reason for this one, it's just a wild guess- Donald said we wouldn't figure it out. This one makes sense, so it's probably not right.
Edit: not Steward... I guess I have Squire on the brain
