All tensioners of this slipper type will wear initially until the grooves cut by the chain side plates are deep enough for the rollers to become the main load bearing elements. The high rate of metallic degradation then becomes negligible, which is why Musky's relatively soft pad can laugh at the chain's muted cutting efforts.
The tensioners were not made with any true precision. The mounting side and curved business end are sometimes not at a true 90 degree angle, and the wear in one cut track is deeper. Many are Hard Chromed, otherwise just a plain stamping. I doubt they are hardened but are nevertheless pretty tough. Making one for the short tem is a simple exercise, but you will need to drain the oil regularly to start with and clear metallic debris from the chaincase. Not so with a used example. The chain needs to have a little bit of slack when hot, but not be board tight when cold. Wobble in the clutch chainwheel allows the chain to move sideways and there are some horrendously abused examples of this mis- understood simple tensioner to be found.
Swarfy.
