How-To Working on some old with ID, method of disassembly

Nov 7, 2001
Ive got a pair of 15" shocks Im going to use on a project...I think they are Showas, but there are no brand markings.
It would be great to find a diagram. I got the caps off the seal area, and the dust boots. What I'm looking at now is a snap ring that's captive. No room to squeeze it in, or expand it or pick it out at all. Was wondering if the sealhead would press down and free up the clip...I found a socket that fit over the shaft and onto the seal head, stacked some spacers and used an impact on a nut on the top of the shaft. Of course the shaft would tend to spin, but the impact was still able to tighten the nut up---but the seal head didn't move.
I could see making a sleeve tool and using the big arbor press I have at work, but that will have to wait until next week, and I don't want to press down on this thing if that's not the way.
At this moment, the shafts action is as follows: for just about half way, it has a spring like resistance and if you let it go it pops back up directly. At about half way, the oil starts flowing and it dampens the rest of the way down, and then half way up at which point it pops up the rest of the way without dampening.
So, it acts as if its low on oil...just not sure why Im getting that initial resistance-without-dampening. Full of air maybe? or nitrogen? there arent any schraeder valves on them anywhere...and no stamped warnings about "pressurized gas" or anything.
Any input would be appreciated!