I'm not real familiar with this engine but the hole you see in the third picture should be there, here's a eBay photo showing it
The cavity the cover is over is a semi dry area, it's open around the crankshaft and blowby from the engine will push oil vapors out enough to keep the starter chain lubricated. The leakage you have could be from the bike having laid on it's left side allowing oil to actually flow into the cavity or there could be too much blowby.
I'd open that area up and clean all the old oil out and reassemble it to ride and see what takes place. You'll need to replace a couple of gasket while doing this.
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