Dog,
The book was written in 1994-1995 time frame.
It's not surprising that this happens. There are, at other times, enormous gaps in S&W's serial number information, or it simply isn't available for use by the authors, or it was somehow omitted when the final edits were being performed on the book.
I'll ask Rick Nahaus, one of the authors of the book I'm talking about, about it next time I see him. He lives in my neck of the woods, and I occasionally run across him at gunshows while we're both sniffing around for deals on used S&W revolvers.
According to the book, your 27-2 was made sometime in 1980. Also according to the book, there were over 200,000 serial numbers blocked out for N-frames in 1980 alone! :eek
Something fishy there, if you ask me.
I think I'm going to give Rick a call tomorrow.