They were all about the same size in the body, but the snap areas were a bit different for some reason. (Incidentally, I ended up not doing the camo onesie. Don't ask me what my logic was, I don't remember.)
I cut the bottoms off at the waist and used an overlock stitch to secure the edge of the fabric. I didn't fold a hem because they would have all ended up being belly shirts. The fabric got jammed several times before I realized (ahem! my mother suggested!) that the fabric was so thin that I needed a stabilizer under it. Some folded tissue paper worked nicely and the last three shirts were done a whole lot faster! I had all five done in less than two hours (rethreading, unjamming and tissue-hunting included).
Here are four of the finished shirts.
And here is the fifth!
This face makes it all completely worth it. (Plus I have five, count 'em five, more shirts in his dresser now and that's not too shabby!) Hooray for onesies recycled into t-shirts!