[Kevin in NJ]

It is common for the shocks to leak. I am still trying to get a handle on the seals as there are at least 2 types when I was looking a while ago. Even more if they were rebuilt a while ago.

Here is my thoughts.

First figure out if they are real originals or a reproduction. We would need better pictures. It is odd that all the fills are stripped. Not sure what is going on there. They are pipe tapped.

You need to take all the shocks off the car.
Put them in a vice and see if they work. You may need to add some oil. They should be really hard to move in one direction and less in the other. If you turn the valve all the way down they should be really really hard to move.

Any play in the shaft and the shock is bad, go no further.

If not then you have a problem. Too many shocks are more decorative then functional.

To get the seal replaced you will need to take apart the cover. This can be a chore and you my need some special tools depending. Once you have the cover off you can try to take the cover off with some big tools. But just take the seal off and see if you have some play on the shaft. Play=no good or maybe work sort of if you put in thicker oil.

The internals of the shock need to be to .001" tolerance or better, I have never seen prints. I know have have some very slightly worn shocks and they do not dampen even close to factory specs.

If the internals seem good you need to clean the cover threads well and see how tight the cover fits screw it on some and see how much play you have. If it rattles around on the threads then use a torch and do some heat shrinks around the cover until it fits more snug. This reduces the oil getting out of the threads. The O rings I have seen are too stiff and do not press into the threads and properly seal. When taking off the covers I do light hammer taps which expand the cover diameter. So I shrink back to a tight fit.

Someone else is going to have to chime in about which shaft and cover seal work.

Just in case, you need to pull the covers to tap the threads so you do not be metal shavings in the oil.

The above is based on my preliminary work on a pile if decent shock I own. I stopped when I found I needed to get a heavier oil and I wanted to make a more accurate KRW copy of the shock testing tool. The tool is basically like a 6 lb weight like 18" or so from the shaft. Be a while so do not take my numbers seriously. My good shocks would take like 5 seconds to drop lock to lock. Specs in the service bulletins say it should take like 15 seconds.