I'm not questioning the legality, comparing a car for FIA spec to a road car is pointless, has it got a FIA cage, internal fuel lines, battery cutoff, battery feed run inside, FIA seats and harnesses? Blocking the vents off for road use because it is in 'some' track use makes no sense to me.
None completely standard,on all the minis I have helped restore(circa 10 cars over the past 6 years) all have had standard fresh air vent corrosion(holes), we plate all the holes up so its easier to clean than with the pipes fitted