It is more plausible that a planchet was struck with 1997 Cent Obverse and 1997 Proof Cent Reverse Dies! The Dies that were designated for Lincoln Cents for a specific year, are retired and locked away before production of the next year. Although in the past (from 1793 to well into the 1800's), the mints were known to use previous or later year designated Dies in an attempt to meet production quotas and demands but that practice ended long ago. In more recent years, they just resort to using Proof Dies when all of the Business Strike Die stock has been exhausted due to Die Failures. It has already been rumored that a 1997 Wide AM Cent discovery exists but has never been certified and Billy Crawford discovered a 1996 Wide AM Cent and as far as I know, it is the only one known. Therefore , it is quite possible that one or more 1997 Wide AM Cents exist but are the result of 1997 Lincoln Cent Obverse Dies and 1997 Proof Lincoln Cent Reverse Dies!
Frank
