due to combustion (due to the heat of the exhaust manifolds) escaping from the carburetors in the event of blockage of the floaters in the low position. Other thing to consider, Lamborghini formed the engine and gearbox in one casting. Its shared lubrication continued until the last 96 SVs, when the case was split to allow the correct oils to be used for each element. An unconfirmed claim holds the first 125 Miuras were built of 0.9 mm steel and are therefore lighter than later cars. All cars had steel frames and doors, with aluminum front and rear skinned body sections. Were the doors, subframes and frames treated against corrosion and rust back then? No, not as far as I read or heard of.
The first generation of Ghibli, don't get me wrong, as much as I like them has its drawbacks too, the fine tuning of multiple carburetion again with 4 Weber 40DCNF and the inability to use fuel unleaded 91 octane gasoline back then in 1973 where USA and Canada were the pioneers by introducing this type of gasoline back in 1971. Another problem regarding the Ghibli, is that there was no treatment against corrosion and rust whether it came to sub-frame connectors, frame and doors.Generally you will very rarely if not never found an unrestored pristine and factory original condition example of a Ghibli or even a Miura with low miles on it.The ones you see have been well maintained over the years and restored to bolt and nut concourse condition and the engine (probably modified with strenghtened valves seats) to use today's unleaded fuel. Also body reconstruction is expensive and with small production cars, it can be very complicated.With a corroded and rusted out chassis and frame, it is even worse.
I hope that my explanations are answering your question.
Have a nice sunday
Best regards
Georges