Pictures might help to see what perhaps you are missing. I do not have any pictures of the particular parts while they are screwed into place with the backs removed but I will try to describe them (from memory).
Screwed to the back side of the upper seat frame, there should be two (black) metal brackets with nylon spacers behind them. Factory Deluxe seat frames have the holes properly pre-drilled (there are two holes per bracket, two brackets per seat) The seat upholstery covers these holes so they need to be located using an awl or the likes (ought to have been done as the upholsetery was installed to find them easiest but they can be located otherwise if you use your hard seat back hooks as a guide) If perhaps you DO NOT have original deluxe seat frames with the holes already in them for the aforementioned brackets, that may be a little more difficult to get the brackets screwed into the correct locations. If that is the case, I do have a pair of seat cores that I could measure or photograph. Ask if needed.
