Got a new rear light from Tim Hodgekiss http://www.vintagemotorspares.com/ last year at the NEC classic show. Unfortunately the studs were not straight. He replaced it I have just got round to trying to fit it. Thought that MOT man might want to see the reversing light working. All the other lights work.
This time I find that the studs are good and straight but too long. They are so long that the bracket that the lamp fits to will not fit back on the boot lid.
Will have to cut the studs shorter. Have got a UNF die to clean the tread up afterwards.