Thanks to all of you for answering some of my novice questions. I am making progress on my first vest. The back turned out well and the front is growing nicely. I have them pinned down for the photos, but not blocked yet. I thought it would be best to block them both at the same time.
The red yarn in the photos are lifelines. I placed one at the last row of 100 stitches before the armhole decrease. I'm glad I did. I miscounted and had to rip out a few inches worth of knitting. It was nice to be able to just rip it out with reckless abandon. The top lifeline is just before I started decreasing for the shoulders and the neck opening.
Any suggestions about joining the pieces together. The instructions didn't say to do anything differently, but I watched a few videos and thought that a chain stitch would work nicely if I used a Kitchener stitch. So, I did a SL1 knitwise at the beginning of each row then followed pattern. At the end of a R side, I ended with a purl stitch. The thing I am concerned about is that the chain stitches are a bit looser than the regular stockinette stitch, but I think I can tighten things up when I am joining. Do any of you more veteran knitters have favorite ways to join pieces together?
As always, thanks for your help.