Thoughts:
Sleeving is only and advantage (due to the cost of new Pistons) if your Old Pistons are still within spec and can be reused.(You will not know if they are still within spec until you take them out and do some measuring.)
If both your Cylinders and the Pistons are worn out and they make oversized pistons for your Engine; that would be the way to go.

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84 300D, 82 Volvo 244Gl Diesel