hi   you left out the most important picture-  that of the cylinder walls do replace the ring  -it is a cheep fix and  can bring the engine back to life  ( ring tension may be gone from too much heat- low oil )-clean the piston with a stay  bright sponge-cross sand the cylinder walls with 320 emery and oil-  at a 45% angles reassemble and break in the new ring-while apart do check the rod for bushing were- (top and bottom ) if worn -consider replace it-do consider these costs -applied to the purchase of a new engine-