Hi Les, I'm not an expert but if after scribing your reference lines on the pressure plate housing and clutch disk and the engine was running and clutch engaged and the marks were still lined up (long sentence) I would suspect the clutch disk is stuck to the flywheel.
I'd try (with engine not running) using the 2x4 to depress the clutch pressure plate, and get under the flywheel to try to pry the clutch disk away.
Someone with more sense than me might have a better idea... just sayin'

Jerry