metal in oil pan

If the cylinders have any kind of ridge you might have a time getting the pistons out without a reamer. If things are within tolerances ,now that you`ve ridge reamed the cylinders to remove the pistons, you might as well hone them and install new rings. Since you`ve gotten it taken apart that far you might as well replace the main and rod bearings. It`s the snowball effect, but you see what I`m getting at. If you can get the pistons out ,I don`t see why you can`t reuse the rings as long as you don`t rotate them on the piston and be sure you put the same piston back in the same cylinder in the same orientation with the same rod bearing.