This video from oorail.com looks at using wire nails and wire brads as an alternative to track pins. The wire brads and nails are solid steel, the brads have a smaller head that is less visible. The video explains why these are better than peco, hornby, javis scenics and other track fixing pins. The size we used in the video are 1/2 x 19. The video has a demonstration of the wire brad being nailed through 1/2" birch plywood.