It's difficult to figure out which of the 737s are combis in the FAA database. According to the Alaska site the combis are "737-400 Combi (73Q)". There are only two 737-73Qs listed in the database, neither of which belong to Alaska, and neither of which appear to be combis
At the same time at least one of the 737-400s (490) Alaska planes in the database are combis, for example
N768AS. This plane was included in my totals above. And yet others, such as
N767AS, are clearly not combi.
If I add up the total planes I can find registered to Alaska and the others with Alaska tail numbers registered to Wells Fargo I get 135 planes. So there's two missing that must be owned by someone else. I wonder who owns them.
Time to do some more digging
Neil