'55.1 had a diagonal saddle with a pivot point on the forward (driver's side) end. Do a search on all forum for "spare tire carrier" and you'll get tons of info on both the early AD slide-out and the later drop racks.
Post an ad in the Swap Meet if yours is missing. I know MT has one, he got his @ss chewed for linking his ebay auction in the Lounge. :rolleyes: