yes the red ink stamp started around 1955-56. The stamp was larger letters and numbers up until around 1960-61. The stamp became the normal size from the 60's then and went to black around late 1965 or so. That puts white painted, pre serial ludwig drum around the 1961-1965 time frame. Ball bat mufflers appeared around 192 as well so that should narrow it down but of coarse the red ink stamps should clear to read if not smudged. Sound like cool drums.