Joe, I use Tichy #1103 .020 phosphor bronze wire, it bends easy and takes brushed paint well. As for the drill I don't know what size, but it is slightly larger than the wire so that once the holes and the rails are painted there is some resistance to keep them in place. The pilot/steps are the original swinging piece from the model, with a spacer plate in between. Bending the new rails is challenging and tedious but to me worth the effort. I'll try to take more detailed photos of the next one I do like this. I need to order some more MU sets from PSC then I think my red/white WM SD35 will be the next one. Aside from that I do have a U30C that has the front end done and just prepped for the back end.