Assuming Knifehunt keeps his word and does not return, I see only one resolution which would satisfy the OP...
Wolfsnagel needs to cross his fingers and his toes that his SNG ends up delivered to Knifehunt's address so that Knifehunt can send it back to him. Barring that, I'm not sure there's much for anyone to do.
Let's pretend Knifehunt did send Wolfsnagel a trade in return (all signs indicate he did not). It would be Knifehunt that would now be out the SNG in this situation since 8 weeks have passed and the knife still has not been delivered. That would be an even bigger mess.... Knifehunt would be demanding that Wolfsnagel return his Medford or whatever.
Under both the current scenario and the pretend scenario above, it's Wolfsnagel that's basically screwed unless his SNG ends up showing as delivered.
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As a side note, someone has been recently trying to use my login here and failing to gain access to my account. I keep getting emails after 5 failed login attempts... Just the nature of the world we live in unfortunately.