Thanks for all the advice. If I don't have to replace anything, I'll just grease everything up and put it back together this afternoon.
I'm glad to know that the retainer isn't necessary. I was worried because when I tried to ride the bike, it made some creaky noise, but not having any lubrication would cause that I believe. I'm glad there doesn't appear to be any crazy pitting, or other damage to everything. I'll let you know how assembly and riding it goes. Thanks again!