So… I found the ‘98 Trek catalog, and yeah, the silver 920 looks exactly like my blue one.
then I took a SN pic, searched and read several pieces on deciphering the various different SN formats without much luck. Photo below.
Looks like the frame was produced late April/early May, but could not confirm the year, which is presumably represented by the letter P.
Looking more closely, you may notice another barely legible stamp running 90 degrees to the P along the non drive side bb edge which reads:
930 16 5, which represents the frame’s model # and size. I’m guessing a leftover frame repainted in the 1998 color scheme.
Maybe that’s why they brought back the 920 in ‘98?