Pictures are always a help but here is my stab at it (as memory serves).
1. The large opening on the bottom of the fitting on the back side is the oil tank breather connection. There shoulde be a brass flame trap that fits in the orifice before the hose is connected to it.
2. The smaller hose on the top of the fitting is the vent line from the gas tank via the charcol cannister.
3. the small opening on the very bottom is a oil collection drip line. It collects oil and sends it to the drip container that is bolted to the back side of the engine oil cooler.
I have seen plastic air boxes that also have a cold start fuel fitting in them too.
Grady you beat me to it again 