The crack in that Motometer lens has probably allowed moisture to infiltrate its guts and create corrosion. I think you can find one in better condition, especially when considering many of these are being removed during cafe racer projects. Determine whether your cluster has round pin or square pin connectors at the back. Although mating up the differing connectors has been done successfully by some owners, having round-to-round or square-to-square connection is desirable.
