So that rubber tube that connects from the crank case to the aircleaner wants to get chucked. It's a PCV tube. No, not a polution control valve, but "positive crankcase ventilation. Thats Bug for air polution control. Useless.
Get rid of that flex pipe from the left head shroud to the aircleaner intake. Cold start preheat also useless.
In fact, get rid of the aircleaner because the two stage Weber downdraft carb you're gonna replace that anemic Zenith carb with has it's own foam rubber air cleaner on top.
Now yer' rolling.