Re: First one.. work in progress??
Good lookin bike.
From the picture it looks like you've got a little head gasket leak on the front left.
Clean off the black stuff with carb cleaner. Re-tighten the acorn nuts, careful not to over do it, and ride.
If it re-appears take of the head and use some 220 grit sandpaper on a flat surface (window glass, granite counter top or equivalent and re-install it.
Sometimes they are warped from the get go.
Good luck and keep the rubber on the road.