I like the latest edition WallylTractor (the full disk). Pivot to spindle must be set with their slick gauge. The mirror on the WallyTractor is a must, otherwise you are guessing on Zenith alignment at the null points. The disk has many arcs for different effective lengths, each with Lofgren or Baerwald for both new and older records. Their online calculator is easy to determine the correct arc. I have set up many tables with it… easy and precise, and one stop shopping.
