Painting bumper clamps

[Barnwood]

Hello,

My dad has a '31.

My dad asked me to tape up his bumper clamp so he could spray paint them blue. It didn't look nice, though. Does anyone have advice on how to paint? I have a very steady hand and could paint it by hand if I knew how to prepare the surface and found good paint. I don't know if the brush strokes would look good, though. My dad is curious how they were painted in 1931.

He bought these plain ones: https://www.snydersantiqueauto.com/p...7181&cat=41657 He didn't want to use decals.

But maybe I could buy these painted ones for him: https://mudsclassicparts.com/1928-19...per-clamp-new/