I'm not sure if it has already been mentioned in this thread so I figured I would throw it out there. I remember back when working on the Apache that it also had a 30 min run dry capability. This was not because things could live without lubrication and didn't get overheated in that amount of time but by use of an oil wicking system. I don't remember all the details but there was supposed to be some felt like material attached to some of the rotating bits in just the right spot that under normal operation would soak up oil. If you took a round through the case and had a total loss of oil this wicking system would, through cetrifugal force, sling out the oil it had soaked up which would keep you going long enough to make it out of a hot area and on the deck. I don't know if this type system could be made to work over a longer period of time and become useful in the off shore arena but I'm sure it would take a major if not complete redesign of a MGB to incorporate so the point is moot.
It does beg the question though...why do we carry our oil in a big metal tub at the bottom of the gear box? Could we not use some sort of oil absorbent material to soak up the oil and release it at a rate which would be sufficient to lube the gears and bearings in an emergency but keep enough of it that one should not lose all the oil in a very short time from a leak. I guess you could think of it as a high tech sponge in the oil sump. When you are full of oil it is saturated and the excess is used to lube the box but if there is a leak the oil drains out of the sponge via gravity (or even at a higher rate due to heat if it could be so designed) and allows continued lubrication for some amount of time.
Just thinking out loud here but it seemed pertinent to the conversation.
Max