Once upon a time a certain UK aircraft manufacturer was asked to supply a modification to the wing of a four engined service plane to strengthen it as its role was being changed to some degree. The company borrowed a frame and manufactured the modification and then went to fit it to the fleet. Alac-a-day oh woe it only fitted one aircraft as the frames were hand built and were all different. The company then had to bodge the mod to complete the job.
Am I repeating a story?, no i'm not. The aircraft was the Victor ,the mod was the cartspring mod to strengthen the wing root but the company, well you've guessed it.