An hour of classics would work - even without the Winston IGASes (I assume the ban is still on?), they can pair WML with whatever they have in their miscellaneous pile. How long has it been since they've aired that one episode of Eye Guess that exists?
I notice Greed isn't on the schedule anywhere - how long has it been since that's been on?
(And if the possibility for "never before on GSN" shows exists, how hard would it be for GSN to get runs of "forgotten" shows like, say, The Chair, or Show Me The Money, or (Fox's) It's Your Chance of a Lifetime? Then again, maybe I shouldn't give GSN any ideas, or we'd probably end up with Unan1mous, You Deserve It, and The Moment of Truth.)