I'm a bit late to the party, but congratulations, CZU that is a nice find!
I have a liking for the Baby Chiefs Special as well. Thus far I have accumulated three, one of each general Baby configuration, round sight, non-serrated (thanks, Bob!), and serrated.
on the discussion of triggers, I too am wondering when the change to a serrated one took place. For those collecting data, I have SN 101, and the trigger is the early non serrated style. (It also has the first style flat latch, and service stocks numbered to the gun.) I'll attach a picture.
This is a good exchange of information for those of us interested in these little things.

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