Lodola Oil leak help please

I know this has been mentioned before under Leaky Lodola but can anyone help me please. I have a 57 175cc Lodola which, having just got back on the road after probably years, leaks an alarming amount of oil from somewhere near the engine chain sprocket under off side casing. Its fine if the engine is just ticking over but noticable after a run… its as if the chain oiler (which I think is from the breather near the afore mentioned sprocket) is working over time dumping out oil. Can anyone help please… is it a blocked breather somewhere else… is there another breather? It has the valve to stop the oil from the tank.

Many thanks