Problems with the Main Gear Box and drive shaft fairings prompted hasty first aid fixes from the manufacturer which then had to be trialled by line pilots on revenue flights, a far from satisfactory state of affairs.
Just looking at my Log Book my first line flight in G-TIGB in May 1982 for BNOC resulted in a diversion to Sumburgh with an MGBCH light.
I can also see that I ferried TIGD when it was green from Marignane to Erith (Metair installed the interiors and Dave Ware's team at Redhill did the spray painting).