3-speed stuck in 3rd

[TheQuicksilver]

Okay, this is a supplement to my project thread. Just wanted to get some more specific help directed my way. Took off the side of my tranny in the 53 today to see what was holding it up. I think the problem with shifting is in the cover assembly, after some feedback in the other thread. But, while in the transmission, I was sliding gears around and noticed the synchronizer drum wouldn't slide over the second speed gear. Is it possible for the synchronizer ring to fail in a way that would cause that to hold up there? Would a problem like that also contribute to making it difficult to get into first and reverse?

What I'd like to do is pull the side back off, and set all the gears into neutral so that I can reassemble it and see how it does fresh from there. Is there any diagram floating about that shows the right gear placement for neutral?