It took far more than an hour...
I think someone was cheatingThe following may help some:
http://www.angelfire.com/ill/motaswalkthroughs/GREENWALL.JPGThe lamp lights up the barrier code.
In that same room there's a key over the ceiling light (need the chair to get to it) that allows you to open the locker for the final key.
LT of the "Spoilers" class.
Ok, this is where I am stuck, where is the friggin barrier code input?