The 2005 date is not a date for an Airworthiness Certificate. It is the date it was first registered (by the current owner, in this case the only owner).
Compare to my Cozy (N228RJ) which was registered in 2010 for the first time but has no AC. It is still a project. Why register? Well, for one thing, it is cheaper than reserving an N number.
The AC date would be at the bottom left (A/W Date). It will be the same or later than the MFR Year, depending on whether or not the AC was ever voided/updated. For my VariEze (N46EZ), my A/W date will soon be changing from 1980 to 2019 since I am adding high compression pistons (major change). My current AC does not allow major changes to be made. The AC becomes void and invalid. But, the MFR Year will always be listed as 1978.
Anyway, that should probably be cleared up before it is sold ... I assume it is a database problem but you never know ...