One more question: what is the other 'can' that isn't the solenoid and is at the very back of the transmission on the same side as the shift plate? In my original message I mentioned its about the size of a soup can and is on the drivers side and is at the very back of the tranny, not the overdrive.
I've looked at a number of manual transmissions in 51 years of driving but have not seen the likes of this. The solenoid I understand now that I have read up on the overdrive unit and would also like to understand this other 'can'.