Rebuilding a shock...doable at home?

I have a pair of older Aldan street rod shocks that are pretty soft. They have a lifetime warranty (for original buyer) so I asked how much to get them rebuilt. $70 for the pair so I dug a little deeper and took one apart. As far as I can tell , there is one friggin O-ring in there! Around the piston...now there are a few seals but they didnt leak before so I'm gonna replace the 1 O-ring and see if it tightens up. They have a knob on the upper mount to adjust damping. They are too short for the rear of an A so Ill probably just sell them. They seem to be old Ford street rod fronts.
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