Welting
The fender welting fits between the fender and the body with the bead of the welting sitting right on top of where the fender meets the body.
My research has not turned up a consistent convention on the colour of the welting. Many of the newer restorations paint the welting to suit the car. The earliest photos I can find show the welting black or what appears to be chrome. In this YouTube link, the restorer wasn’t too fussed that the welting didn’t perfectly match the paint.
Video “how to” fender welting.
