Well, you're right!
I went back and looked under the model 317 listings itself rather than the serial number listing and it shows some "LGT" prefix guns being made in 1997.
Just an FYI, but S&W has been offering some "no lock" J frame models for the last couple years, which is what I assumed this was.
Of course, you know what they say about assuming...
Yup, but unfortunately not the 317's as far as I know.
I bought a couple when they first came out, and gave one to a friend for his wife. Getting hard to find in pre lock now.