Thanks Dean. I seem to have avoided having to do the entire clutch cover gasket replacement by smearing a small amount of Permatex Right Stuff into the interface (you can't even see it after I cleaned it up). After looking at the gasket itself I can see that the area in which it is leaking is one side of a cell that houses an oil passage or something. I reckon at some stage the cover really needed to be retorqued and nobody ever did that, so it blew. I have all tha parts on hand if it does ever resurface, but it seems to be holding up for now.
I've replaced the clutch slave cylinder using an Oberon part and that appears to be fixed now. I can't believe how powerful these bikes are, it's straight insane.