Oil in airbox

[Flashman400]

changed my air filter today and noticed some oil in the airbox - see photos. presume this is not normal? what would cause it? also on top of the airbox there appears to be a small filter of some sort with a tube that connects to the middle of pipe that runs across the carbs. It's more or less disintegrated as you can see in the 3rd photo. anyone know what it's for and what I should replace it with? thanks!

[pptom]

I shouldn't worry about the oil, it just come from the engine breather.
The little filter thing is just regular foam, they disintegrate over time. I replaced mine on the vfr with a bit of car wash sponge cut to shape.