There are a few doubled dies on the proof cents. So you might want to check Variety Vista for what to look for.
http://varietyvista.com/01b%20LC%20...9PDDO003.htmBut the coin listed is no big deal for a doubled die. I wonder why they listed it? Look like a polished proof die that shows all the date and Liberty as even smaller than normal.
From the image provided, the full images are no help. The two showing Liberty are normal.
Coppercoins.com might be a better choice:
But no proof listings for them at all.
Wexler's doubled dies might help:
http://doubleddie.com/344622.htmlBut again no proof cents listed. But I would like to have you check out this last page. He does show a lot of doubled dies on this page. That way you can know what your looking for. Read all comments. That will help along the way. But again no listing for proofs on this site. (Just business strike coins)