The plan was to repair the top hydraulic cylinder on the SLK230, paint the hood and top on the Cavalier, then to put the third in the Fiero but as Murphy says "Anything that can go wrong, will go wrong!" and this is the case with the Mercedes top cylinder.
I was actually able to rebuild the cylinder in place, without having to remove it from the car but in doing so, had to destroy the retainer clip holding the rod seal and bearing in place. I thought finding a new retaining clip would be easy but that has not proved to be the case. I found two companies who make the standard listed retaining clip, but both of them required that I purchase 100 of them at $3.50 each, so tried to use a standard snap ring. Being the groove for the wire retaining clip is 20 mm and a snap ring is just square, the retaining clip pushed out when operating the top. Now the top of the SLK230 was stuck in the down position and I could not get to the release cord on the passenger side of the car. After grinding the pin on the mounting point of the cylinder, I was able to rebuild the cylinder again, this time making a retaining ring out of a key chain ring. The top is finally closed but it still blew the seal out again, so I ordered another cylinder from EBAY to get a new clip. $100 for the whole cylinder was still cheaper than the $350 for 100 wire retaining rings at $3.50 each.
There is a car show in Lancaster, OH on Saturday, which is close enough I could drive the car there and back so I may try to get the interior back together enough to take it but am not sure I can get everything back together by then. Anyway, as soon as the Mercedes top cylinders are back together and the Cavalier top and hood are repainted, I will get back on putting the third module back in the Fiero.