1987 Toyota MR2 friction point on the clutch changed

1987 Toyota MR2 mileage: 133,800. About 4 months ago I was driving normally and suddenly the friction point on the clutch changed. It used to be right in the middle of the clutch pedal travel, and very narrow. When it changed, it moved noticeably further up the pedal travel and became broader. I eventually adjusted to this change and was not concerned about it. Lately, in the last few weeks, when the car is cold there is a bucking as I let out the clutch from a stop. This is even in warm weather. It feels as if my foot is shaking on the clutch pedal as I let it out (but it's not). This goes away after about 5 minutes of driving the car. Yesterday while working under the dash, I noticed a brownish-gray fluid all over the firewall behind the clutch pedal. It seems to be coming from where the clutch pedal rod goes through the firewall to (I assume) the clutch master cylinder. I do not know how long this stuff has been dripping but there is a fairly wide stream going down the firewall and underneath the carpet. I have all the maintenance records from the previous owners of the car, and the clutch, pressure plate, and throw out bearing were replaced at 90,000 miles. There is no record to indicate the clutch master cylinder has been replaced. What is wrong with this car? What could have caused the sudden change in the friction point? I long for the old friction point again...