Just read another member frustrated by having to "duplicate" a part for a project. My first thought is: if they are not close together, your eyes don't see the small differnces. I turn legs by the hundreds by eye and memory and a caliper for size. Look at the chair in the other post I made and it is not apparent to the viewer the turning differences that are obvious when separated. Do your best and it will come. In my case I had to stop scraping at the lathe and that was a major improvement in my resuls. As always, keep the tools sharp and touch them up as you go.