Neil, none of the CRJ's you listed on your blog are operated by Horizon for Alaska. They are now flying with Atlantic Southeast/SkyWest/Express Jet for Delta Connection.
There are still two Horizon CRJ's that are unaccounted for:
N616QX, now a Delta Connection plane.
N290RB (the albino) that never flew in Horizon livery.
The freighter/combi list:
Freighter:
N709AS (-490)
Combi:
N762AS (-4Q8)
N763AS (-4Q8)
N764AS (-4Q8)
N765AS (-4Q8)
N768AS (-490)