Looks like it's actually a 92 according to vintage trek. Have you tried unscrewing the inner limit screw to see if that lets it shift to little ring?
If no joy, have you tried disconnecting the cable from the FD to see if it then shifts to little ring?
It looks like an awfully small radius run-around at the bottom. Is it perhaps missing a pulley down there? What exactly is the cable wrapped around at the bottom of the run?