what would the cost of labor and parts to rebuild the hydrolic cyclinders on my

Many SL owners have their cylinders rebuilt by independent craftsmen instead of buying replacement cylinders from the dealer or from on-line suppliers; rebuild cost is about 1/3 of replacement cost. The rebuilder I've personally used is Dennis Ficken, Tel. 913-390-0506; quality work, fast turnaround, lengthy and trustworthy warranty. Whatever you end up doing, avoid the temptation to add any 'stop-leak' type of product to the reservoir; you'll run the risk of ruining all the cylinder seals through a negative chemical reaction.