Google up "road draft tube" - it's a metal tube, usually with a 45* slant tip, that points down towards the road and ends about where the bottom of the
oil pan is. All cars used to have these. The idea was that air rushing past the slant tip would create a slight vacuum and pull fumes out of the crankcase... where, of course, they would just dissipate into the atmosphere, never harming nobody.
This is also the reason all roads used to have a black oily line down the center of each lane. Since this wasn't acceptable on race tracks, the puke tank was used to catch (in theory) the liquid
oil.
Also:
AFAIK, no engines had vents or tubes or breathers on the valve covers until the advent of smog controls in the early 1960s, and performance engines lagged behind road engines. I'd be surprised if any original Cobra engine had them.