I think I may have found the watch that is my personal grail. The attached picture borrowed from Scubawatch.org shows a Longines UltraChron Diver. I really like minamalist treatment of the 7970-1 case. I would like to know what other lines the case was used in? I think I've seen an Admiral Five and a Record that used the same case. I have also heard that some Admiral divers used the 431 movement. The Adimral Five I saw had a 505 movement is this movement completely different than the 431?