[Peter Graham]

Late to the game here (haven't read entire thread): the generator pulley in the last photo is a VW part. It is a larger diameter than the stock 912 pulley so the 'extra' 5mm shouldn't be a surprise. It also means that the generator/fan are not spinning as fast as they would if the correct pulley was mounted. And yes, the hub is trashed (usually from not running enough shims). Belt should run in the crank pulley groove nearest the motor (outer pulley was for air pump - MY68 only).

Because of other factors, you may encounter pulley alignment issues: if someone mounted a VW pulley, there could be kludges to 'attempt' alignment, including improper/improper assembly of 'pie plates' (sheet metal that bolts to fan shroud).

BTW, 8 shims are minimum for 912 generator pulleys; I run 10 to ensure nut is doing its job.

Peter