After six months working on this project, I am finally done! I finished seaming up the sides of the vest yesterday after work and when I got home, I threw it in the washer, along with some towels, set on delicates mode. Once that was done, I tossed everything in the dryer on the knits setting, which uses a cooler temperature. I let that go for about 20 minutes before changing the temp to a higher heat. The dryer went for another 20 minutes and when I pulled the vest out, it looked great. The stitches were a bit tighter and more uniform. When I measured it against another size large sweater, it was exactly the same size instead of about four inches longer, like it was when I measured it against the same sweater last week. Mission accomplished!
PS This vest is a gift, so I'll have photos of it being modeled after I give it away in a week or so.