My 47 3100 had no caulking. It must have departed long ago. I wanted to retain the patina but stop further deterioration as well. So I taped off about 1/4 inch above and below the seam and media blasted with the black stuff from HFT. It looked so nice afterwards I just scuffed it and primed with red oxide primer. Then found the closest satin rattle can paint I cound find and dusted a light coat.
