I went with the mother of pearl buttons that so many of you suggested. I really like how they are neutral but kind of dressy at the same time.
The back is my favorite part with that high slit.
The buttons were made with my Greist buttonholer on my Necchi BU Mira.
I finally conquered that Burda technique that they show with the wooden spoon. It's pretty easy when you actually follow their directions. You pull the vest right side out through a 6" slit in the CB lining. Later you hand-stitch that puppy back together.

Let's see, some details for ya'll. I took in the side seams about an inch on both sides. I made no other alterations except leaving off the topstitching, tubular braid, frog closures, and snaps. Brian, it took me almost no time to make this vest. It's only six pieces (three fashion fabric, three lining) with no challenging sewing. I think it probably took me four hours of solid time from tracing to buttonholes. Like everything, the pressing and finishing things like buttonholes and hand-stitching took the majority of time. Actual time at the machine might have been an hour but I doubt it. I highly recommend making vests because they don't require much fitting and they are simple and fast to put together.