S&W Wood Target Grips for K and N Frame Revolvers

[DaBull]

For a long while, S&W made wood target grips with inset medallions that were installed using a washer/disk, but some of their newer grips (circa 80s) did not use the washers/disks. The washers are useful because they can be used to help determine at a glance if the grips are for a K/L or an N frame revolver by looking at the size of the "nub" of wood on the back side of the washer. Does anyone have an easy way to determine if a pair of target grips without the washer is for a K or N frame revolver?