I'm not sure you are completely done with the top cover. When the 1/2 shifter shaft glides as smoothly as the 3/4 shifter shaft you will be done with that. So if more effort needs to be applied to that, try attaching the top cover to the transmission such that you can bolt one top cover bolt to the top of the transmission and the cover and shifting forks are in mid air (not in the transmission). The purpose is to use the transmission to hold the top cover so you can shift the shifter between 1st and 2nd gears and get that freed up.
The other half of the story is what you just posted. You should be able to move the clusters with your hands, they need to be able to glide over the main shaft easily. If not, it's tap, tap, tap, spray, spray, repeat until they do move. Try not to hammer the edges of the grears and wear some eye protection. I used a piece of wood and hammered on it.
This should fill in your weekend. Good luck.
