Trying to find something in the original post that suggests the replacement property was depreciable.  Appears that the California property was just land.  

Not that I trust AI, but it tells me that "California’s "claw-back" provision (AB 92), requiring taxpayers to track and report deferred gain when exchanging California property for out-of-state property, was enacted on June 27, 2013, and became effective for tax years beginning on or after January 1, 2014."  Must be some newbies around here suggesting that there's a Form 3840 problem that goes back 20 years.