TSM,
So you saw 246 when she was parked, overnight, at the Run bay adjacent to the Flying club.......yet you made reference to the "extensive corrosion"....I have to say that, as somebody who witnessed and overviewed the strip first hand, both internally and externally, there was relatively little corrosion other than on the areas I have mentioned. Consequently, the aircraft had not been exposed to the elements in the way you infer other than in it's former operational role of course. Believe me TSM, we all had a damn good look at the structure as we stripped the a/c....and there was a wealth of engineering experience on the team I assure you.
I will reiterate therefore that, the internal and indeed external structure was not, as you say, extensively corroded. With regard to the wing box section which you display, again, a close inspection will reveal that the level of corrosion you imply to be present, simply wasn't. You may be interested to learn that, when the wings were cut off,the state of the internal structure was as sound as when it was constructed, as was the PRC.
In this instance TSM, whilst I am normally in agreement with your posts, I have to say you are mistaken in your perceptions.