Grumpy you may have been thinking of my Greenfield seeing we only just covered it. It has the adjustable screw locknut on the rod running from the pedal. Just for the record it seems a more simple setup on mine.
Having the minute amount of experience I have with these machines I would be looking into the guts of the clutch system.
If anything, if it hasn't been apart for the life if the machine it would be a good time for an inspection and service.
