318 poly wide block

This is WRONG. When disk wears the pedal goes UP, and the release is closer to the TOP of the pedal travel. FORGET clutch "worn disk" for the moment. Try and discover why it is not releasing as you have been

It's POSSIBLE that sand, gravel, mud, and "pieces of clutch disc" have become wedged in between the rear of the actual pressure plate and the framework of the pressure plate behind it known as the "clutch cover."

Here:

View attachment 1715061959

If enough "junk" becomes stuck between the pressure plate marked "plate" in this diagram and the cover, it could do exactly as yours is.

So could I just clean everything? But if I have to take the transmission apart anyway I should just go ahead and replace the clutch too right? I mean at least then there would be a new clutch in it that I wouldn't have to worry about for hopefully quite some time, given it is driven properly.