contemporary 35mm lens for the M2

[Nokton48]

How do the silver/chrome vintage filters differ from ones made today? Are there ribs on the older ones versus a smooth surface on the present ones?

The early chrome Leitz filters I own have identical ribbing, exactly matching the front rings of my V1 Rigid Summicron, and V1 50mm F2.8 Elmar. So it all matches up exactly, and looks really good, to me.