I would change the filter next, those are inexpensive and can usually cause hesitation. If it is 5 years old that is a good guess. As far as the plug wires, do a visual inspection, als the plugs are cheap, so I would replace those next, you can get an idea of the condition of your engine by inspecting the old plugs when you remove them. Give those a try, if they have not been replaced as of yet it is a good idea to do it as part of maintenance. Keep in mind when you buy an SL it will take awhile to get the car up to your standards, and into a regular maintenance regimen. It took me a year to get my car just right, so be patient, those cars have the fuel distributor on them, so don't let it sit around, it is not good for it.
Good luck!
Brian

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Brian W. Heitman

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