As requested, here is a step-by-step pictorial of how I convert Atlas HO code 83 turnouts to On30. I went this route for two reasons. One - The Peco On30 track is lovely, but I wanted code 83 rail, not code 100. Two - I had loads of code 83 track and turnouts, and being a cheap fella, wanted to use that up. So, off we go. Here are what I started with; rather than laboriously identify each item, I'll just include what I used in the picture.