BOAC did indeed repair a 707 where the wing virtually fell off as a result of a ground fire. A schoolfriends father was one of the project engineers.
I imagine that this kind of engineering was more feasible back then due to less complex materials and production methods and certainly wouldnt be possible on 'plastic aeroplanes'. . I wonder how far an ace car mechanic of the 60s would get with even a fairly humble 2020 family car