You haven't mentioned whether you are going to replace the piston rings. They do wear out, but I have no idea how much work your engine has done. Usually the piston and bore will outlast 2 or more sets of rings, provided the engine is always kept full of clean oil. Dirty oil wears out the piston and bore, as well as the crankpin.
If you measure the piston ring gaps we can talk about whether they need to be replaced. Measure the gaps with feeler gauges, with the rings 1 cm down the bore from the top. Make sure they are square to the bore by pushing them down with the top of the (upside-down) piston.
