It rotates with the crankshaft, and does not sit flush with the clutch basket but prevents it's removal. It was full of oil when I opened it, appeared to be the same consistence/viscosity as my engine oil so I pesume it is open at the other side. There is nothing in the casing, apart from the clutch lever. Havnt had the left side off yet but will have a look tomorrow.
Nice to here your still biking Alex. Havn't done much myself since Scotland last year. Are you still rocking a Terra?