I don't have my serial number references handy, but IIRC early S&W 3rd-gen 9mm TDA pistols were all lumped together in the same serial number range, starting with TCAxxx in late 1988.
FWIW early 3rd-gen M390x, M590x, and M690x series pistols all had squared-off trigger guards with checkered fronts, and the standard fixed rear sight was a very square vertical blade. The fixed rear sight was changed to a much less snaggy Novak Lo-Mount unit in 1991, and the trigger guards were rounded off 2-3 years later (the M390x series never got the latter change because they were discontinued by then). IOW early fixed sights + square trigger guard = 1988-1990 production; Novak fixed sights + square trigger guard = 1991-1994ish production; round trigger guard = later.
"Smokey, this is not 'Nam. This is bowling. There are rules... MARK IT ZERO!!" - Walter Sobchak