Expert eyes needed

Please elaborate . I have no friggin idea what the brass blocking teeth are. I CAN tell ya all the teeth on all gears and brass things ARE pretty pointed.
Also, what do you mean by "on the way down".

I can put you together a 10 second engine that will live damn near forever, but I'm totally clueless in the tranny department. Always had someone do them for me. Would like to stop that now......