Afternoon All Knowledgeable one's,

I have a large old set chrome head lights from I think a Westfield/Caterham, one has the nut missing to secure it to the car.

it looks like a UNF thread around 9/16" or 5/8", does anyone know the size for sure ? and where to get a nut/lock washer ?

any assistance will be gratefully received.

regards Ian

My plan of action would be to take it to a local nut and bolt shop and check the fit before buying. They should be able to help you and provide washers too. My local fastner trade counter is very helpful and as a bonus the counter guy is quite interested in cars.