You may want to try to identify if the ACPS for the ARR-7 is a ham-built unit or built by R.E. Goodheart company of California in the early 1960s. One of those did show up with the rec on Epay last year, i think, and it went for something like $400-500. BTW, has anyone ever seen an actual 3-dimensional ARR-7X ? -Hue Miller