[Shotimes] clutch disengagement problem

[David Eberwine]

My 91 has 80K on the stock ford clutch/pressure plate with stock
steel-sleeved-spline TOB assembly. I did the work circa 96.  Clutch
cable was replaced at the same time and pressure/travel appears to be
fine.  I never keep the clutch extended at stops and I bump the throttle
to slide it out of 5th gear so there is really minimal use on the
thing.  The clutch grip is fine.  Full engagement is about an inch from
the top of pedal travel with about a half inch of movement to create
slippage (the main slip/engagement window).  Pedal force is fairly
constant across the full range of pedal travel up to full engagement.
The problem is that there is a slight engagement in clutch with pedal
travel all the way to the floor - small but enough that a tach drop is
visible and it will actually pull the car with the pedal a half inch off
the floor.  So its like 2.5 inches of ever so slight engagement followed
by the normal 1/2 inch to full engagement area.  Anyone run across and
diagnosed this?

Could a bolt have worked out of the pressure plate to flywheel after 7
years?
Could the pressure plate have a physical problem with a pressure plate
finger resulting in continued contact at full extension?

7 years ago I had more time and desire to crawl under the car....

Regards,
David