The vest is seamed and I've done two rows of single crochet around the arms, but I'm not sure that the 5 or 6 rows I have planned are going to keep the bottom from rolling up. It's not blocked yet, so that will help. If it doesn't hold I'll just have to go with a ribbed band.
If you're looking for buttons, check Cathy's links in the comments to my previous entry. I found some winners!