When the liftgate is in the closed down position the sliding brackets point upward. Manually push up on them and they pull the liftgate tight thru a lever action. Then tighten the knurled knobs to secure the tight position. See pic. Bill
That's all that holds them up,they don't work very well.I have been tempted to grind notches in the top of the slot but never got around to it.As they are I never put the gate up,would never stay up when driving.Phil
I have seen an outside latch on a 41/48 wagon mounted in the center lower rail and it is butt ugly! What I did to make access to the liftgate sliders from the outside was to eliminate the rear side window lock and place a small dowel or molding in the felt window channel to keep the window jammed shut like a shortened broomstick handle you would use to secure a patio door. Open your rear doors take the dowels out then you can slide your rear side glass forward from the outside giving you access to the knurled knobs from the outside. Primitive maybe but has worked for me for 35 years...Bill