Fixing fuel shut-off valve on a '47 H

I've read a post that says (paraphrased): unscrew the hold-down nut and remove that and the part that screws in and out to close and open the valve, get a neoprene "O" ring that fits tight over the shaft, remove all the old packing and put the "O" ring in its place, reassemble. I'd like to know beforehand where this old packing is. Is the order of elements: hold-down nut, packing around the bent screw-in-and-out valve shaft, screw-in-and-out valve shaft, valve seat? Or is the packing between the screw-in-and-out 'male' part of the valve and the 'female' seat of the valve? Sorry about the tortured naming of these parts - I'm trying to be clear.

I tried unscrewing the hold-down nut and then thought I'd be able to pull it and the screw-in-and-out valve shaft together. I wasn't able to do so easily so I figured I'd better get a view of what's going on from the experts before I break anything.

Thanks,

Dave