From here it was simple to get the inner case open to expose the gearbox and some nasty grunge.
The other side of the engine is where problem number two is. I can't remove the clutch mechanism from the shaft. I've tried the Haynes improvised tool but it doesn't budge - even a little. I think I'm going to have to find the tool. In the mean time I have the gearbox to disassemble and the wheels to attend to. That should keep me busy while I find the tool.
The other item to procure is a set of Whitworth wrenches. I've been trying to snag a set on e-bay but the prices have been higher than I want to pay so far. I've found some new wrench sets I can get for about the same price as the old ones so I'll probably be ordering some of those for Christmas.