yeah proly time for a swap or sell the thing to someone who wants a roller to start with.
Id bet rings are worn, best start would be a cylinder leak down test and compression test just to determine the health of the motor. Pull a plug or two and see how they look, maybe even replace the plugs and drive it then pull the plugs and see what the engine is telling you.
Either way for the most part unless the car is cherry or you are doing work yourself or himself it is proly not worth it.