Halfway through doing it right now... The bolt where the 1 inch of gasket was blown out was loose! I wouldn't have been able to replace the gasket with sealant though... Even though I left it to drain overnight, there was oil leaking out the join, because inside the sump there's these fin "channels" that were still holding oil.

Maybe if I'd left it upright I might have been able, but the crankshaft oil seal is weeping slightly too. So I may replace that as well while it's apart.

BTW...

When I used to work on VCRs, there were little arrows on the nylon gears that were used to line up the timing correctly. I saw a similar arrow on what I assume is either a cam for the valves, and/or oil pump. I *think* I've managed to keep it in the same position it was when I removed the sump - but - is there a more certain method I should use to set the timing before reassembling?