Nial;
Not absolutely positive, but I don't think the crimp head itself was "Improved" again after that cataloged at least as early as 1950. Should be no patent problem on that, course if you stamped "Lyman" on it there would be Copyright problems. This head has a sort of "Ratchet" type configuration in the bottom of the groove, not a real easy form to obtain without some specialized equipment.

Miller/TN
I Didn't Say Everything I Said, Yogi Berra