Bavaria 47 steering chain sprocket

[Nigel]

My boat partner thought he heard a noise coming from the area of the steering chain sprocket when the dual steering chains meet, prior to the autohelm; he took this picture:



It seems that the sprocket is held on the shaft by a Woodruff Key, with a circlip on the right-hand end. The Woodruff Key was partly visible (not in this picture) and was loose, also there appears to be a ring of grease on the shaft where the sprocket may have moved.

Does anyone have any info on who made the steering mechanism on a Bavaria 47, built 2000? Or perhaps an exploded diagram or parts list?