Thanks. Apparently, they are not just going to change the fluid, but they're also going to pressure test the system some how to see if perhaps there is a leak somehow. Based on the result, they'll decide whether the clutch problem is being caused by leak or something else - or maybe just contaminants in the fluid. I don't have anyone here to help me try it myself. And I don't know how to pressure test the system. I'll report back.
Since I posted, I called two other dealers - another near Westchester. NY is
89 an hour, and one near Hartford, CT where I used to live is 80. I'm not concerned about paying for the fluid change and test. But if the slave cylinder needs to be replaced, along with the clutch, etc., that will be a huge bill - maybe even more than my 92 is worth (though the vehicle remains immaculate) Haven't even worn the original brakes much. I really baby this thing.