sadly i try not to understand how it all works, too many turny things for my brain to comprehend at once. alternately, I try to make sure each part works as it should and be in the right spot and hasn't been messed with.
everything looks normal in picts but.... why is there weld splatter in your tranny, i see it, its been messed with. all it takes is one of those little balls to fu any of those bearings.
from rt to left.
when turning motor 1st gear clutch spins freely, clutch bell dont move.
check one way bearing n cage, on intermediate shaft. sprag spring there?
last when u hold that peanut spring twist the claw collar, there should be resistance.is the ext pedal spring and washer installed, opposite side and is it the right one?
run a small magnet around to pick up all that weld splatter too.