If Bill Jordan received a pre-production prototype, this is the first I have heard of it (not to say he didn't). But I know for sure that K260001, a 4-screw, and the second gun completed, was shipped to him on January 5, 1956. As published in History of Smith & Wesson, page 182, by Roy Jinks, this is the revolver Mr. Jordan used when he appeared on "You Asked For It", a popular TV show in the 50s. K260004 (with a dark blue presentation case) was shipped on January 20, 1956 to Major General Julian Hatcher of the NRA and featured in the March 1956 issue of the American Rifleman.
Bill