looks good , the old carb with the dust/leak appearance kinda normal , they all will look a tiny bit wet and collect dust, pushing a tiny bit out is ok , when it starts sucking back in is the problem.
the exhaust coupler is a hassle, blown out countless, esp. as you add power. the stock rarely blew out, but everything else without fail. i used an aluminum pipe cover, crinkle wrap for plumbing pipe joints, simple, very effective easy to work with and completely covers joint material, just add it in under clamps.
the grease seal on the air filter , it is also oiled and in compression right ?